diff --git a/app/app_procs.c b/app/app_procs.c
index b59941fa94..f5ea8d5e89 100644
--- a/app/app_procs.c
+++ b/app/app_procs.c
@@ -15,15 +15,26 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+#include "config.h"
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
+#ifdef _MSC_VER
+#include <process.h>		/* For _getpid() */
+#endif
+ 
 #include <gtk/gtk.h>
 
 #include "libgimp/gimpfeatures.h"
@@ -73,8 +84,6 @@
 #include "color_notebook.h"
 #include "color_select.h"
 
-#include "config.h"
-
 #include "libgimp/gimpintl.h"
 
 #define LOGO_WIDTH_MIN 300
@@ -169,21 +178,22 @@ splash_logo_load_size (GtkWidget *window)
   if (logo_pixmap)
     return TRUE;
 
-  g_snprintf (buf, sizeof(buf), "%s/gimp1_1_splash.ppm", DATADIR);
+  g_snprintf (buf, sizeof(buf), "%s" G_DIR_SEPARATOR_S "gimp1_1_splash.ppm",
+	      DATADIR);
 
   fp = fopen (buf, "rb");
   if (!fp)
     return 0;
 
-  fgets (buf, 1024, fp);
+  fgets (buf, sizeof (buf), fp);
   if (strcmp (buf, "P6\n") != 0)
     {
       fclose (fp);
       return 0;
     }
 
-  fgets (buf, 1024, fp);
-  fgets (buf, 1024, fp);
+  fgets (buf, sizeof (buf), fp);
+  fgets (buf, sizeof (buf), fp);
   sscanf (buf, "%d %d", &logo_width, &logo_height);
 
   fclose (fp);
@@ -204,24 +214,25 @@ splash_logo_load (GtkWidget *window)
   if (logo_pixmap)
     return TRUE;
 
-  g_snprintf (buf, sizeof(buf), "%s/gimp1_1_splash.ppm", DATADIR);
+  g_snprintf (buf, sizeof(buf), "%s" G_DIR_SEPARATOR_S "gimp1_1_splash.ppm",
+	      DATADIR);
 
   fp = fopen (buf, "rb");
   if (!fp)
     return 0;
 
-  fgets (buf, 1024, fp);
+  fgets (buf, sizeof (buf), fp);
   if (strcmp (buf, "P6\n") != 0)
     {
       fclose (fp);
       return 0;
     }
 
-  fgets (buf, 1024, fp);
-  fgets (buf, 1024, fp);
+  fgets (buf, sizeof (buf), fp);
+  fgets (buf, sizeof (buf), fp);
   sscanf (buf, "%d %d", &logo_width, &logo_height);
 
-  fgets (buf, 1024, fp);
+  fgets (buf, sizeof (buf), fp);
   if (strcmp (buf, "255\n") != 0)
     {
       fclose (fp);
@@ -273,6 +284,7 @@ splash_text_draw (GtkWidget *widget)
 		   ((logo_area_width - gdk_string_width (font, NAME)) / 2),
 		   (0.25 * logo_area_height),
 		   NAME);
+  gdk_font_unref (font);
 
   font = gdk_font_load ("-Adobe-Helvetica-Bold-R-Normal--*-120-*-*-*-*-*-*");
   gdk_draw_string (widget->window,
@@ -293,6 +305,7 @@ splash_text_draw (GtkWidget *widget)
 		   ((logo_area_width - gdk_string_width (font, AUTHORS)) / 2),
 		   (0.80 * logo_area_height),
 		   AUTHORS);
+  gdk_font_unref (font);
 }
 
 static void
@@ -424,7 +437,7 @@ app_init_update_status(char *label1val,
 	{
 	  while ( strlen (label2val) > max_label_length )
 	    {
-	      temp = strchr (label2val, '/');
+	      temp = strchr (label2val, G_DIR_SEPARATOR);
 	      if (temp == NULL)  /* for sanity */
 		break;
 	      temp++;
@@ -462,7 +475,7 @@ app_init (void)
   gimp_dir = gimp_directory ();
   if (gimp_dir[0] != '\000')
     {
-      g_snprintf (filename, MAXPATHLEN, "%s/gtkrc", gimp_dir);
+      g_snprintf (filename, MAXPATHLEN, "%s" G_DIR_SEPARATOR_S "gtkrc", gimp_dir);
 
       if ((be_verbose == TRUE) || (no_splash == TRUE))
 	g_print (_("parsing \"%s\"\n"), filename);
@@ -539,7 +552,8 @@ app_init (void)
   if (swap_path == NULL)
     swap_path = "/tmp";
   toast_old_temp_files ();
-  path = g_strdup_printf ("%s/gimpswap.%ld", swap_path, (long)getpid ());
+  path = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "gimpswap.%ld",
+			  swap_path, (long)getpid ());
   tile_swap_add (path, NULL, NULL);
   g_free (path);
 
@@ -759,9 +773,17 @@ toast_old_temp_files (void)
          */
 
 	int pid = atoi (entry->d_name + 9);
+#ifndef NATIVE_WIN32
 	if (kill (pid, 0))
+#else
+	/* On Windows, you can't remove open files anyhow,
+	 * so no harm trying.
+	 */
+#endif
+
 	  {
-	    g_string_sprintf (filename, "%s/%s", swap_path, entry->d_name);
+	    g_string_sprintf (filename, "%s" G_DIR_SEPARATOR_S "%s",
+			      swap_path, entry->d_name);
 	    unlink (filename->str);
 	  }
       }
diff --git a/app/appenv.h b/app/appenv.h
index bdd91bd4bc..1bef566c6a 100644
--- a/app/appenv.h
+++ b/app/appenv.h
@@ -19,11 +19,23 @@
 #define __APPENV_H__
 
 #include "glib.h"
+
+/* The GIMP shouldn't need to know much about X11 (or Windows), so
+ * I'll remove this inclusion of gdkx.h. This will speed up compilations
+ * a bit, too. If some source file needs gdkx.h, it can include it.
+ */
+#if 0
 #include "gdk/gdkx.h"
+#endif
+
 #include "gtk/gtk.h"
 #include "gimpsetF.h"
 #include "colormap_dialog.t.h"
+
+/* Without gdkx.h no GDK_DISPLAY() */
+#if 0
 #define DISPLAY              ((Display *) GDK_DISPLAY())
+#endif
 
 /*   important macros - we reuse the ones from glib */
 #define BOUNDS(a,x,y)  CLAMP(a,x,y)
diff --git a/app/asupsample.c b/app/asupsample.c
index 29d63d5fdb..7121b10848 100644
--- a/app/asupsample.c
+++ b/app/asupsample.c
@@ -30,6 +30,7 @@
 
 
 #include <math.h>
+#include <stdlib.h>
 
 #include "appenv.h"
 #include "asupsample.h"
diff --git a/app/base/temp-buf.c b/app/base/temp-buf.c
index ca3b6a6268..af4faa1caa 100644
--- a/app/base/temp-buf.c
+++ b/app/base/temp-buf.c
@@ -15,12 +15,22 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <string.h>
 #include <sys/stat.h>
+
+#ifdef _MSC_VER
+#include <process.h>		/* For _getpid() */
+#endif
+ 
 #include "appenv.h"
 #include "drawable.h"
 #include "errors.h"
@@ -416,7 +426,8 @@ generate_unique_filename (void)
 {
   pid_t pid;
   pid = getpid ();
-  return g_strdup_printf ("%s/gimp%d.%d", temp_path, (int) pid, swap_index++);
+  return g_strdup_printf ("%s" G_DIR_SEPARATOR_S "gimp%d.%d",
+			  temp_path, (int) pid, swap_index++);
 }
 
 
diff --git a/app/base/tile-manager.c b/app/base/tile-manager.c
index 05aa0588c8..f4e56f305a 100644
--- a/app/base/tile-manager.c
+++ b/app/base/tile-manager.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <string.h>
+
 #include "tile_cache.h"
 #include "tile_manager.h"
 #include "tile_swap.h"
diff --git a/app/base/tile-swap.c b/app/base/tile-swap.c
index fbff8e511e..b94f520f1a 100644
--- a/app/base/tile-swap.c
+++ b/app/base/tile-swap.c
@@ -1,13 +1,21 @@
+#include "config.h"
+
 #include <errno.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #ifdef USE_PTHREADS
 #include <pthread.h>
 #endif
 
+#ifdef _MSC_VER
+#include <io.h>
+#endif
+
 #include "libgimp/gimpintl.h"
 
 #define MAX_OPEN_SWAP_FILES  16
@@ -352,7 +360,11 @@ tile_swap_open (SwapFile *swap_file)
       nopen_swap_files -= 1;
     }
 
+#ifndef NATIVE_WIN32
   swap_file->fd = open (swap_file->filename, O_CREAT|O_RDWR, S_IRUSR|S_IWUSR);
+#else
+  swap_file->fd = open (swap_file->filename, O_CREAT|O_RDWR|_O_BINARY, _S_IREAD|_S_IWRITE);
+#endif
   if (swap_file->fd == -1)
     {
       g_message (_("unable to open swap file...BAD THINGS WILL HAPPEN SOON"));
diff --git a/app/batch.c b/app/batch.c
index 896b86e4f8..9dd9d9d57f 100644
--- a/app/batch.c
+++ b/app/batch.c
@@ -1,9 +1,13 @@
+#include "config.h"
+
 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "app_procs.h"
@@ -43,10 +47,14 @@ batch_init ()
 	{
 	  if (!read_from_stdin)
 	    {
+#ifndef NATIVE_WIN32 /* for now */
 	      g_print (_("reading batch commands from stdin\n"));
 	      gdk_input_add (STDIN_FILENO, GDK_INPUT_READ, batch_read, NULL);
 	      read_from_stdin = TRUE;
 	    }
+#else
+	      g_error ("Batch mode from standard input not implemented on Win32");
+#endif
 	}
       else
 	{
diff --git a/app/blob.c b/app/blob.c
index 71e960e55b..d62a34b4b2 100644
--- a/app/blob.c
+++ b/app/blob.c
@@ -31,6 +31,10 @@
 
 #define ROUND(A) floor((A)+0.5)
 
+#ifndef M_PI
+#define M_PI    3.14159265358979323846
+#endif /* M_PI */
+
 static Blob *
 blob_new (int y, int height)
 {
diff --git a/app/clone.c b/app/clone.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/clone.c
+++ b/app/clone.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/color_area.c b/app/color_area.c
index ae86ca4355..cfdec2506d 100644
--- a/app/color_area.c
+++ b/app/color_area.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "color_area.h"
 #include "color_notebook.h"
diff --git a/app/color_select.c b/app/color_select.c
index eaee373af3..757daf9db5 100644
--- a/app/color_select.c
+++ b/app/color_select.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "actionarea.h"
 #include "color_select.h"
diff --git a/app/colormap_dialog.i.c b/app/colormap_dialog.i.c
index de4bc30d60..a8675a2d69 100644
--- a/app/colormap_dialog.i.c
+++ b/app/colormap_dialog.i.c
@@ -429,9 +429,11 @@ ipal_clear (GimpColormapDialog* ipal)
 
   palette = GTK_WIDGET(ipal->palette);
 
-  width = palette->allocation.width;
-  height = palette->allocation.height;
-  row = g_new(guchar, width * 3);
+  /* Watch out for negative values (at least on Win32) */
+  width = (int) (gint16) palette->allocation.width;
+  height = (int) (gint16) palette->allocation.height;
+  if (width > 0)
+    row = g_new(guchar, width * 3);
   
   gtk_preview_size(ipal->palette, width, height);
   
@@ -448,7 +450,8 @@ ipal_clear (GimpColormapDialog* ipal)
       for (j = 0; j < 4 && i+j < height; j++)
 	gtk_preview_draw_row (ipal->palette, row, 0, i + j, width);
     }
-  g_free (row);
+  if (width > 0)
+    g_free (row);
   gtk_widget_draw (palette, NULL);
 }
 
diff --git a/app/core/gimpbrushgenerated-load.c b/app/core/gimpbrushgenerated-load.c
index 162ac4b320..d273fdcf9f 100644
--- a/app/core/gimpbrushgenerated-load.c
+++ b/app/core/gimpbrushgenerated-load.c
@@ -18,12 +18,24 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include "appenv.h"
 #include "gimpbrushgenerated.h"
 #include "paint_core.h"
 #include "gimprc.h"
-#include <math.h>
-#include <stdio.h>
 
 #define OVERSAMPLING 5
 
@@ -228,7 +240,7 @@ gimp_brush_generated_generate(GimpBrushGenerated *brush)
   register double exponent;
   register guchar a;
   register int length;
-  register char *lookup;
+  register guchar *lookup;
   double buffer[OVERSAMPLING];
   register double sum, c, s, tx, ty;
   int width, height;
diff --git a/app/core/gimpbrushgenerated-save.c b/app/core/gimpbrushgenerated-save.c
index 162ac4b320..d273fdcf9f 100644
--- a/app/core/gimpbrushgenerated-save.c
+++ b/app/core/gimpbrushgenerated-save.c
@@ -18,12 +18,24 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include "appenv.h"
 #include "gimpbrushgenerated.h"
 #include "paint_core.h"
 #include "gimprc.h"
-#include <math.h>
-#include <stdio.h>
 
 #define OVERSAMPLING 5
 
@@ -228,7 +240,7 @@ gimp_brush_generated_generate(GimpBrushGenerated *brush)
   register double exponent;
   register guchar a;
   register int length;
-  register char *lookup;
+  register guchar *lookup;
   double buffer[OVERSAMPLING];
   register double sum, c, s, tx, ty;
   int width, height;
diff --git a/app/core/gimpbrushgenerated.c b/app/core/gimpbrushgenerated.c
index 162ac4b320..d273fdcf9f 100644
--- a/app/core/gimpbrushgenerated.c
+++ b/app/core/gimpbrushgenerated.c
@@ -18,12 +18,24 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include "appenv.h"
 #include "gimpbrushgenerated.h"
 #include "paint_core.h"
 #include "gimprc.h"
-#include <math.h>
-#include <stdio.h>
 
 #define OVERSAMPLING 5
 
@@ -228,7 +240,7 @@ gimp_brush_generated_generate(GimpBrushGenerated *brush)
   register double exponent;
   register guchar a;
   register int length;
-  register char *lookup;
+  register guchar *lookup;
   double buffer[OVERSAMPLING];
   register double sum, c, s, tx, ty;
   int width, height;
diff --git a/app/core/gimpdatafiles.c b/app/core/gimpdatafiles.c
index da558448b9..74aba57d30 100644
--- a/app/core/gimpdatafiles.c
+++ b/app/core/gimpdatafiles.c
@@ -18,15 +18,29 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
-
+#include "config.h"
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
+
+#ifdef _MSC_VER
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+#ifndef S_IXUSR
+#define S_IXUSR _S_IEXEC
+#endif
+#endif
 
 #include <glib.h>
 #include "datafiles.h"
@@ -70,7 +84,7 @@ datafiles_read_directories (char *path_str,
 
   next_token = local_path;
 
-  token = xstrsep(&next_token, ":");
+  token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
 
   while (token)
     {
@@ -90,8 +104,8 @@ datafiles_read_directories (char *path_str,
 
       if (!err && S_ISDIR(filestat.st_mode))
 	{
-	  if (path[strlen(path) - 1] != '/')
-	    strcat(path, "/");
+	  if (path[strlen(path) - 1] != G_DIR_SEPARATOR)
+	    strcat(path, G_DIR_SEPARATOR_S);
 
 	  /* Open directory */
 	  dir = opendir(path);
@@ -124,7 +138,7 @@ datafiles_read_directories (char *path_str,
 
       g_free(path);
 
-      token = xstrsep(&next_token, ":");
+      token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
     } /* while */
 
   g_free(local_path);
diff --git a/app/core/gimpdrawable.c b/app/core/gimpdrawable.c
index 738d35fd8e..f9cd6dbd6d 100644
--- a/app/core/gimpdrawable.c
+++ b/app/core/gimpdrawable.c
@@ -19,7 +19,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
-#include <strings.h>
+#include <string.h>
 #include "gimpdrawableP.h"
 #include "gimpsignal.h"
 #include "gimage.h"
diff --git a/app/core/gimpparasitelist.c b/app/core/gimpparasitelist.c
index 95d9678ce9..11cc0b1c39 100644
--- a/app/core/gimpparasitelist.c
+++ b/app/core/gimpparasitelist.c
@@ -15,6 +15,8 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <string.h>
+
 #include "gimpobjectP.h"
 #include "gimpobject.h"
 #include "gimpsignal.h"
diff --git a/app/core/gimpprojection.c b/app/core/gimpprojection.c
index 1d00870219..45a4f91db0 100644
--- a/app/core/gimpprojection.c
+++ b/app/core/gimpprojection.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "buildmenu.h"
 #include "channels_dialog.h"
diff --git a/app/datafiles.c b/app/datafiles.c
index da558448b9..74aba57d30 100644
--- a/app/datafiles.c
+++ b/app/datafiles.c
@@ -18,15 +18,29 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
-
+#include "config.h"
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
+
+#ifdef _MSC_VER
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+#ifndef S_IXUSR
+#define S_IXUSR _S_IEXEC
+#endif
+#endif
 
 #include <glib.h>
 #include "datafiles.h"
@@ -70,7 +84,7 @@ datafiles_read_directories (char *path_str,
 
   next_token = local_path;
 
-  token = xstrsep(&next_token, ":");
+  token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
 
   while (token)
     {
@@ -90,8 +104,8 @@ datafiles_read_directories (char *path_str,
 
       if (!err && S_ISDIR(filestat.st_mode))
 	{
-	  if (path[strlen(path) - 1] != '/')
-	    strcat(path, "/");
+	  if (path[strlen(path) - 1] != G_DIR_SEPARATOR)
+	    strcat(path, G_DIR_SEPARATOR_S);
 
 	  /* Open directory */
 	  dir = opendir(path);
@@ -124,7 +138,7 @@ datafiles_read_directories (char *path_str,
 
       g_free(path);
 
-      token = xstrsep(&next_token, ":");
+      token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
     } /* while */
 
   g_free(local_path);
diff --git a/app/dialogs/module-dialog.c b/app/dialogs/module-dialog.c
index fc168c339c..85ba129503 100644
--- a/app/dialogs/module-dialog.c
+++ b/app/dialogs/module-dialog.c
@@ -18,10 +18,15 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#include <time.h>
 
 #include "appenv.h"
 #include "module_db.h"
@@ -335,16 +340,14 @@ module_info_free (module_info *mod)
 /* helper functions */
 
 
-/* name must be of the form lib*.so */
-/* TODO: need support for WIN32-style dll names.  Maybe this function
- * should live in libgmodule? */
+/* name must be of the form lib*.so (Unix) or *.dll (Win32) */
 static gboolean
 valid_module_name (const char *filename)
 {
   const char *basename;
   int len;
 
-  basename = strrchr (filename, '/');
+  basename = strrchr (filename, G_DIR_SEPARATOR);
   if (basename)
     basename++;
   else
@@ -352,6 +355,7 @@ valid_module_name (const char *filename)
 
   len = strlen (basename);
 
+#ifndef WIN32
   if (len < 3 + 1 + 3)
     return FALSE;
 
@@ -360,6 +364,10 @@ valid_module_name (const char *filename)
 
   if (strcmp (basename + len - 3, ".so"))
     return FALSE;
+#else
+  if (g_strcasecmp (basename + len - 4, ".dll"))
+    return FALSE;
+#endif
 
   return TRUE;
 }
diff --git a/app/dialogs/preferences-dialog.c b/app/dialogs/preferences-dialog.c
index 3d353f49a6..ddf5b0d825 100644
--- a/app/dialogs/preferences-dialog.c
+++ b/app/dialogs/preferences-dialog.c
@@ -1,5 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+
 #include "appenv.h"
 #include "about_dialog.h"
 #include "actionarea.h"
diff --git a/app/dialogs/tips-dialog.c b/app/dialogs/tips-dialog.c
index ca89dcaf62..956d7977cd 100644
--- a/app/dialogs/tips-dialog.c
+++ b/app/dialogs/tips-dialog.c
@@ -45,9 +45,11 @@ tips_dialog_create ()
   if (tips_count == 0)
     {
       if ((gimp_data_dir = getenv ("GIMP_DATADIR")) != NULL)
-        temp = (char *) g_strdup_printf ("%s/%s", gimp_data_dir, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 gimp_data_dir, TIPS_FILE_NAME);
       else
-        temp = (char *) g_strdup_printf ("%s/%s", DATADIR, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 DATADIR, TIPS_FILE_NAME);
       read_tips_file ((char *)temp);
       g_free (temp);
     }
@@ -219,7 +221,7 @@ read_tips_file (char *filename)
   char *tip = NULL;
   char *str = NULL;
 
-  fp = fopen (filename, "rb");
+  fp = fopen (filename, "r");
   if (!fp)
     {
       store_tip (_("Your GIMP tips file appears to be missing!\n"
diff --git a/app/disp_callbacks.c b/app/disp_callbacks.c
index 80efbf0e81..b49d7bd380 100644
--- a/app/disp_callbacks.c
+++ b/app/disp_callbacks.c
@@ -329,7 +329,7 @@ gdisplay_canvas_events (GtkWidget *canvas,
 	      /*  if the first mouse button is down, check for automatic
 	       *  scrolling...
 	       */
-	      if ((mevent->state & Button1Mask) && !active_tool->scroll_lock)
+	      if ((mevent->state & GDK_BUTTON1_MASK) && !active_tool->scroll_lock)
 		{
 		  if (mevent->x < 0 || mevent->y < 0 ||
 		      mevent->x > gdisp->disp_width ||
diff --git a/app/display/gimpdisplay-callbacks.c b/app/display/gimpdisplay-callbacks.c
index 80efbf0e81..b49d7bd380 100644
--- a/app/display/gimpdisplay-callbacks.c
+++ b/app/display/gimpdisplay-callbacks.c
@@ -329,7 +329,7 @@ gdisplay_canvas_events (GtkWidget *canvas,
 	      /*  if the first mouse button is down, check for automatic
 	       *  scrolling...
 	       */
-	      if ((mevent->state & Button1Mask) && !active_tool->scroll_lock)
+	      if ((mevent->state & GDK_BUTTON1_MASK) && !active_tool->scroll_lock)
 		{
 		  if (mevent->x < 0 || mevent->y < 0 ||
 		      mevent->x > gdisp->disp_width ||
diff --git a/app/display/gimpdisplay.c b/app/display/gimpdisplay.c
index 1d00870219..45a4f91db0 100644
--- a/app/display/gimpdisplay.c
+++ b/app/display/gimpdisplay.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "buildmenu.h"
 #include "channels_dialog.h"
diff --git a/app/display/gimpdisplayshell-callbacks.c b/app/display/gimpdisplayshell-callbacks.c
index 80efbf0e81..b49d7bd380 100644
--- a/app/display/gimpdisplayshell-callbacks.c
+++ b/app/display/gimpdisplayshell-callbacks.c
@@ -329,7 +329,7 @@ gdisplay_canvas_events (GtkWidget *canvas,
 	      /*  if the first mouse button is down, check for automatic
 	       *  scrolling...
 	       */
-	      if ((mevent->state & Button1Mask) && !active_tool->scroll_lock)
+	      if ((mevent->state & GDK_BUTTON1_MASK) && !active_tool->scroll_lock)
 		{
 		  if (mevent->x < 0 || mevent->y < 0 ||
 		      mevent->x > gdisp->disp_width ||
diff --git a/app/docindex.c b/app/docindex.c
index e8217c70b2..de6d16fa90 100644
--- a/app/docindex.c
+++ b/app/docindex.c
@@ -13,14 +13,15 @@
  * GNU General Public License for more details.
  */
 
-#include "docindexif.h"
-#include "docindex.h"
-
-#include <gtk/gtk.h>
 #include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 
+#include <gtk/gtk.h>
+
+#include "docindexif.h"
+#include "docindex.h"
+
 idea_manager *ideas = NULL;
 static GList *idea_list = NULL;   /* of gchar *. */
 static gint x = 0, y = 0, width = 0, height = 0;
diff --git a/app/docindexif.h b/app/docindexif.h
index 7fca830e41..684b4e4ba6 100644
--- a/app/docindexif.h
+++ b/app/docindexif.h
@@ -18,7 +18,6 @@
 
 
 #include <ctype.h>
-#include <gdk/gdkprivate.h>
 #include <stdio.h>
  
 #include "libgimp/gimpintl.h"
diff --git a/app/errorconsole.c b/app/errorconsole.c
index 7badb122c4..004eb8fb32 100644
--- a/app/errorconsole.c
+++ b/app/errorconsole.c
@@ -19,15 +19,32 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <errno.h>
 #include <fcntl.h>
 #include <sys/stat.h>
-#include "gtk/gtk.h"
+
+#ifdef _MSC_VER
+#include <io.h>
+#ifndef S_IRUSR
+#define S_IRUSR _S_IREAD
+#endif
+#ifndef S_IWUSR
+#define S_IWUSR _S_IWRITE
+#endif
+#endif
+
+#include <gtk/gtk.h>
 
 #include "commands.h"
 #include "session.h"
diff --git a/app/errors.c b/app/errors.c
index 6a920c6d1d..7d63cf486a 100644
--- a/app/errors.c
+++ b/app/errors.c
@@ -15,14 +15,24 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <signal.h>
 #include <stdarg.h>
 #include <stdio.h>
+#include <stdlib.h>
+#ifdef HAVE_SYS_TIME_H
 #include <sys/time.h>
+#endif
+#ifdef HAVE_SYS_TIMES_H
 #include <sys/times.h>
+#endif
 #include <sys/types.h>
 #include <time.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include <gtk/gtk.h>
 #include "appenv.h"
diff --git a/app/fileops.c b/app/fileops.c
index d8be7fd469..899114466c 100644
--- a/app/fileops.c
+++ b/app/fileops.c
@@ -16,16 +16,29 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <ctype.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/types.h>
+#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
+#endif
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <errno.h>
 
+#ifdef _MSC_VER
+#include <process.h>		/* For _getpid() */
+#include <direct.h>		/* For _mkdir() */
+#define mkdir(path,mode) _mkdir(path)
+#endif
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "cursorutil.h"
@@ -534,7 +547,8 @@ file_open_callback (GtkWidget *w,
       if (GTK_WIDGET_VISIBLE (fileload))
 	return;
 
-      gtk_file_selection_set_filename (GTK_FILE_SELECTION(fileload), "./");
+      gtk_file_selection_set_filename (GTK_FILE_SELECTION(fileload),
+				       "." G_DIR_SEPARATOR_S);
       gtk_window_set_title (GTK_WINDOW (fileload), _("Load Image"));
     }
 
@@ -707,7 +721,8 @@ file_save_as_callback (GtkWidget *w,
       if (GTK_WIDGET_VISIBLE (filesave))
 	return;
 
-      gtk_file_selection_set_filename (GTK_FILE_SELECTION(filesave), "./");
+      gtk_file_selection_set_filename (GTK_FILE_SELECTION(filesave),
+				       "." G_DIR_SEPARATOR_S);
       gtk_window_set_title (GTK_WINDOW (filesave), _("Save Image"));
     }
 
@@ -1386,9 +1401,9 @@ file_open_ok_callback (GtkWidget *w,
   if (err == 0 && (buf.st_mode & S_IFDIR))
     {
       GString *s = g_string_new (filename);
-      if (s->str[s->len - 1] != '/')
+      if (s->str[s->len - 1] != G_DIR_SEPARATOR)
         {
-          g_string_append_c (s, '/');
+          g_string_append_c (s, G_DIR_SEPARATOR);
         }
       gtk_file_selection_set_filename (fs, s->str);
       g_string_free (s, TRUE);
@@ -1549,7 +1564,7 @@ file_save_ok_callback (GtkWidget *w,
       if (buf.st_mode & S_IFDIR)
 	{
 	  GString *s = g_string_new (filename);
-	  g_string_append_c (s, '/');
+	  g_string_append_c (s, G_DIR_SEPARATOR);
 	  gtk_file_selection_set_filename (fs, s->str);
 	  g_string_free (s, TRUE);
 	  return;
@@ -2106,7 +2121,8 @@ file_temp_name_invoker (Argument *args)
   if (id == 0)
     pid = getpid();
 
-  g_string_sprintf (s, "%s/gimp_temp.%d%d.%s", temp_path, pid, id++, (char*)args[0].value.pdb_pointer);
+  g_string_sprintf (s, "%s" G_DIR_SEPARATOR_S "gimp_temp.%d%d.%s",
+		    temp_path, pid, id++, (char*)args[0].value.pdb_pointer);
 
   return_args = procedural_db_return_args (&file_temp_name_proc, TRUE);
 
diff --git a/app/gdisplay.c b/app/gdisplay.c
index 1d00870219..45a4f91db0 100644
--- a/app/gdisplay.c
+++ b/app/gdisplay.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "buildmenu.h"
 #include "channels_dialog.h"
diff --git a/app/general.c b/app/general.c
index 70ddee2d06..3d5b563811 100644
--- a/app/general.c
+++ b/app/general.c
@@ -22,6 +22,13 @@
 #include <sys/stat.h>
 #include <time.h>
 #include <glib.h>
+
+#ifdef _MSC_VER
+#ifndef S_ISREG
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+#endif
+
 #include "general.h"
 
 char*
@@ -34,14 +41,14 @@ search_in_path (char *search_path,
   int err;
 
   local_path = g_strdup (search_path);
-  token = strtok (local_path, ":");
+  token = strtok (local_path, G_SEARCHPATH_SEPARATOR_S);
 
   while (token)
     {
       sprintf (path, "%s", token);
 
-      if (token[strlen (token) - 1] != '/')
-	strcat (path, "/");
+      if (token[strlen (token) - 1] != G_DIR_SEPARATOR)
+	strcat (path, G_DIR_SEPARATOR_S);
       strcat (path, filename);
 
       err = stat (path, &buf);
@@ -51,7 +58,7 @@ search_in_path (char *search_path,
 	  break;
 	}
 
-      token = strtok (NULL, ":");
+      token = strtok (NULL, G_SEARCHPATH_SEPARATOR_S);
     }
 
   g_free (local_path);
diff --git a/app/gimpbrushgenerated.c b/app/gimpbrushgenerated.c
index 162ac4b320..d273fdcf9f 100644
--- a/app/gimpbrushgenerated.c
+++ b/app/gimpbrushgenerated.c
@@ -18,12 +18,24 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
+#include <math.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include "appenv.h"
 #include "gimpbrushgenerated.h"
 #include "paint_core.h"
 #include "gimprc.h"
-#include <math.h>
-#include <stdio.h>
 
 #define OVERSAMPLING 5
 
@@ -228,7 +240,7 @@ gimp_brush_generated_generate(GimpBrushGenerated *brush)
   register double exponent;
   register guchar a;
   register int length;
-  register char *lookup;
+  register guchar *lookup;
   double buffer[OVERSAMPLING];
   register double sum, c, s, tx, ty;
   int width, height;
diff --git a/app/gimpbrushlist.c b/app/gimpbrushlist.c
index 6d54b3c883..5b802db08c 100644
--- a/app/gimpbrushlist.c
+++ b/app/gimpbrushlist.c
@@ -15,14 +15,22 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <math.h>
+
 #include "appenv.h"
 #include "gimpbrushgenerated.h"
 #include "brush_header.h"
diff --git a/app/gimpdrawable.c b/app/gimpdrawable.c
index 738d35fd8e..f9cd6dbd6d 100644
--- a/app/gimpdrawable.c
+++ b/app/gimpdrawable.c
@@ -19,7 +19,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <math.h>
-#include <strings.h>
+#include <string.h>
 #include "gimpdrawableP.h"
 #include "gimpsignal.h"
 #include "gimage.h"
diff --git a/app/gradient.c b/app/gradient.c
index 0730bdc4f9..787c3fda79 100644
--- a/app/gradient.c
+++ b/app/gradient.c
@@ -148,12 +148,15 @@
  * - Add a Gradient brush mode (color changes as you move it).
  */
 
+#include "config.h"
 
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
@@ -168,7 +171,6 @@
 #include "session.h"
 #include "gradient_header.h"
 
-#include "config.h"
 #include "libgimp/gimpintl.h"
 
 /***** Magic numbers *****/
@@ -5970,17 +5972,20 @@ build_user_filename(char *name, char *path_str)
 	home        = g_get_home_dir ();
 	local_path  = g_strdup(path_str);
 	first_token = local_path;
-	token       = xstrsep(&first_token, ":");
+	token       = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 	filename    = NULL;
 
 	if (token) {
 		if (*token == '~') {
+			if (!home)
+				return NULL;
 			path = g_strdup_printf("%s%s", home, token + 1);
 		} else {
 			path = g_strdup(token);
 		} /* else */
 
-		filename = g_strdup_printf("%s/%s", path, name);
+		filename = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
+					   path, name);
 
 		g_free(path);
 	} /* if */
diff --git a/app/gradient_editor.c b/app/gradient_editor.c
index 0730bdc4f9..787c3fda79 100644
--- a/app/gradient_editor.c
+++ b/app/gradient_editor.c
@@ -148,12 +148,15 @@
  * - Add a Gradient brush mode (color changes as you move it).
  */
 
+#include "config.h"
 
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
@@ -168,7 +171,6 @@
 #include "session.h"
 #include "gradient_header.h"
 
-#include "config.h"
 #include "libgimp/gimpintl.h"
 
 /***** Magic numbers *****/
@@ -5970,17 +5972,20 @@ build_user_filename(char *name, char *path_str)
 	home        = g_get_home_dir ();
 	local_path  = g_strdup(path_str);
 	first_token = local_path;
-	token       = xstrsep(&first_token, ":");
+	token       = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 	filename    = NULL;
 
 	if (token) {
 		if (*token == '~') {
+			if (!home)
+				return NULL;
 			path = g_strdup_printf("%s%s", home, token + 1);
 		} else {
 			path = g_strdup(token);
 		} /* else */
 
-		filename = g_strdup_printf("%s/%s", path, name);
+		filename = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
+					   path, name);
 
 		g_free(path);
 	} /* if */
diff --git a/app/gradient_select.c b/app/gradient_select.c
index b4a44c643a..98a017c379 100644
--- a/app/gradient_select.c
+++ b/app/gradient_select.c
@@ -34,11 +34,15 @@
  * the structures so we can find which one we are taking about.
  */
 
+#include "config.h"
+
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
diff --git a/app/gui/color-area.c b/app/gui/color-area.c
index ae86ca4355..cfdec2506d 100644
--- a/app/gui/color-area.c
+++ b/app/gui/color-area.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "color_area.h"
 #include "color_notebook.h"
diff --git a/app/gui/color-select.c b/app/gui/color-select.c
index eaee373af3..757daf9db5 100644
--- a/app/gui/color-select.c
+++ b/app/gui/color-select.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "actionarea.h"
 #include "color_select.h"
diff --git a/app/gui/gradient-editor.c b/app/gui/gradient-editor.c
index 0730bdc4f9..787c3fda79 100644
--- a/app/gui/gradient-editor.c
+++ b/app/gui/gradient-editor.c
@@ -148,12 +148,15 @@
  * - Add a Gradient brush mode (color changes as you move it).
  */
 
+#include "config.h"
 
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
@@ -168,7 +171,6 @@
 #include "session.h"
 #include "gradient_header.h"
 
-#include "config.h"
 #include "libgimp/gimpintl.h"
 
 /***** Magic numbers *****/
@@ -5970,17 +5972,20 @@ build_user_filename(char *name, char *path_str)
 	home        = g_get_home_dir ();
 	local_path  = g_strdup(path_str);
 	first_token = local_path;
-	token       = xstrsep(&first_token, ":");
+	token       = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 	filename    = NULL;
 
 	if (token) {
 		if (*token == '~') {
+			if (!home)
+				return NULL;
 			path = g_strdup_printf("%s%s", home, token + 1);
 		} else {
 			path = g_strdup(token);
 		} /* else */
 
-		filename = g_strdup_printf("%s/%s", path, name);
+		filename = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
+					   path, name);
 
 		g_free(path);
 	} /* if */
diff --git a/app/gui/gradient-select.c b/app/gui/gradient-select.c
index b4a44c643a..98a017c379 100644
--- a/app/gui/gradient-select.c
+++ b/app/gui/gradient-select.c
@@ -34,11 +34,15 @@
  * the structures so we can find which one we are taking about.
  */
 
+#include "config.h"
+
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
diff --git a/app/gui/module-browser.c b/app/gui/module-browser.c
index fc168c339c..85ba129503 100644
--- a/app/gui/module-browser.c
+++ b/app/gui/module-browser.c
@@ -18,10 +18,15 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#include <time.h>
 
 #include "appenv.h"
 #include "module_db.h"
@@ -335,16 +340,14 @@ module_info_free (module_info *mod)
 /* helper functions */
 
 
-/* name must be of the form lib*.so */
-/* TODO: need support for WIN32-style dll names.  Maybe this function
- * should live in libgmodule? */
+/* name must be of the form lib*.so (Unix) or *.dll (Win32) */
 static gboolean
 valid_module_name (const char *filename)
 {
   const char *basename;
   int len;
 
-  basename = strrchr (filename, '/');
+  basename = strrchr (filename, G_DIR_SEPARATOR);
   if (basename)
     basename++;
   else
@@ -352,6 +355,7 @@ valid_module_name (const char *filename)
 
   len = strlen (basename);
 
+#ifndef WIN32
   if (len < 3 + 1 + 3)
     return FALSE;
 
@@ -360,6 +364,10 @@ valid_module_name (const char *filename)
 
   if (strcmp (basename + len - 3, ".so"))
     return FALSE;
+#else
+  if (g_strcasecmp (basename + len - 4, ".dll"))
+    return FALSE;
+#endif
 
   return TRUE;
 }
diff --git a/app/gui/palette-editor.c b/app/gui/palette-editor.c
index 5ebaa47c78..ceb9186ad7 100644
--- a/app/gui/palette-editor.c
+++ b/app/gui/palette-editor.c
@@ -15,11 +15,18 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
 #include "appenv.h"
@@ -1257,20 +1264,25 @@ palette_create_entries(gpointer   client_data,
 	  home = g_get_home_dir ();
 	  local_path = g_strdup (palette_path);
 	  first_token = local_path;
-	  token = xstrsep(&first_token, ":");
+	  token = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 
 	  if (token)
 	    {
 	      if (*token == '~')
 		{
-		  path = g_strdup_printf("%s%s", home, token + 1);
+		  if (home)
+		    path = g_strdup_printf("%s%s", home, token + 1);
+		  else
+		    /* Just ignore the ~ if no HOME ??? */
+		    path = g_strdup(token + 1);
 		}
 	      else
 		{
 		  path = g_strdup(token);
 		}
 
-	      entries->filename = g_strdup_printf ("%s/%s", path, palette_name);
+	      entries->filename = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+						   path, palette_name);
 
 	      g_free (path);
 	    }
diff --git a/app/gui/palette-select.c b/app/gui/palette-select.c
index c15ec9d9f9..80c5c58239 100644
--- a/app/gui/palette-select.c
+++ b/app/gui/palette-select.c
@@ -17,13 +17,17 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
-#include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "buildmenu.h"
diff --git a/app/gui/preferences-dialog.c b/app/gui/preferences-dialog.c
index 3d353f49a6..ddf5b0d825 100644
--- a/app/gui/preferences-dialog.c
+++ b/app/gui/preferences-dialog.c
@@ -1,5 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+
 #include "appenv.h"
 #include "about_dialog.h"
 #include "actionarea.h"
diff --git a/app/gui/tips-dialog.c b/app/gui/tips-dialog.c
index ca89dcaf62..956d7977cd 100644
--- a/app/gui/tips-dialog.c
+++ b/app/gui/tips-dialog.c
@@ -45,9 +45,11 @@ tips_dialog_create ()
   if (tips_count == 0)
     {
       if ((gimp_data_dir = getenv ("GIMP_DATADIR")) != NULL)
-        temp = (char *) g_strdup_printf ("%s/%s", gimp_data_dir, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 gimp_data_dir, TIPS_FILE_NAME);
       else
-        temp = (char *) g_strdup_printf ("%s/%s", DATADIR, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 DATADIR, TIPS_FILE_NAME);
       read_tips_file ((char *)temp);
       g_free (temp);
     }
@@ -219,7 +221,7 @@ read_tips_file (char *filename)
   char *tip = NULL;
   char *str = NULL;
 
-  fp = fopen (filename, "rb");
+  fp = fopen (filename, "r");
   if (!fp)
     {
       store_tip (_("Your GIMP tips file appears to be missing!\n"
diff --git a/app/main.c b/app/main.c
index 8950853f0a..91affb2db6 100644
--- a/app/main.c
+++ b/app/main.c
@@ -22,8 +22,13 @@
 #include <signal.h>
 #include <string.h>
 #include <sys/types.h>
+#ifdef HAVE_SYS_WAIT_H
 #include <sys/wait.h>
+#endif
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+
 #include "libgimp/gserialize.h"
 
 #ifndef  WAIT_ANY
@@ -40,7 +45,9 @@
 #include "libgimp/gimpintl.h"
 
 static RETSIGTYPE on_signal (int);
+#ifdef SIGCHLD
 static RETSIGTYPE on_sig_child (int);
+#endif
 static void       init (void);
 static void       test_gserialize();
 static void	  on_error (const gchar* domain,
@@ -137,7 +144,7 @@ main (int argc, char **argv)
   no_data = FALSE;
   no_splash = FALSE;
   no_splash_image = FALSE;
-#ifdef HAVE_SHM_H
+#if defined (HAVE_SHM_H) || defined (NATIVE_WIN32)
   use_shm = TRUE;
 #else
   use_shm = FALSE;
@@ -274,7 +281,7 @@ main (int argc, char **argv)
 
   if (show_help)
     {
-      g_print (_("\007Usage: %s [option ...] [files ...]\n"), argv[0]);
+      g_print (_("Usage: %s [option ...] [files ...]\n"), argv[0]);
       g_print (_("Valid options are:\n"));
       g_print (_("  -h --help                Output this help.\n"));
       g_print (_("  -v --version             Output version info.\n"));
@@ -300,18 +307,38 @@ main (int argc, char **argv)
   g_set_message_handler ((GPrintFunc) message_func);
 
   /* Handle some signals */
+#ifdef SIGHUP
   signal (SIGHUP, on_signal);
+#endif
+#ifdef SIGINT
   signal (SIGINT, on_signal);
+#endif
+#ifdef SIGQUIT
   signal (SIGQUIT, on_signal);
+#endif
+#ifdef SIGABRT
   signal (SIGABRT, on_signal);
+#endif
+#ifdef SIGBUS
   signal (SIGBUS, on_signal);
+#endif
+#ifdef SIGSEGV
   signal (SIGSEGV, on_signal);
+#endif
+#ifdef SIGPIPE
   signal (SIGPIPE, on_signal);
+#endif
+#ifdef SIGTERM
   signal (SIGTERM, on_signal);
+#endif
+#ifdef SIGFPE
   signal (SIGFPE, on_signal);
+#endif
 
+#ifdef SIGCHLD
   /* Handle child exits */
   signal (SIGCHLD, on_sig_child);
+#endif
 
   g_log_set_handler(NULL,
 		    G_LOG_LEVEL_ERROR | G_LOG_FLAG_FATAL,
@@ -332,6 +359,18 @@ main (int argc, char **argv)
   return 0;
 }
 
+#ifdef NATIVE_WIN32
+
+/* In case we build this as a windowed application */
+
+int _stdcall
+WinMain (int hInstance, int hPrevInstance, char *lpszCmdLine, int nCmdShow)
+{
+  return main (__argc, __argv);
+}
+
+#endif
+
 static void
 init ()
 {
@@ -356,45 +395,67 @@ static RETSIGTYPE
 on_signal (int sig_num)
 {
   if (caught_fatal_sig)
-/*    raise (sig_num);*/
+#ifdef NATIVE_WIN32
+    raise (sig_num);
+#else
     kill (getpid (), sig_num);
+#endif
   caught_fatal_sig = 1;
 
   switch (sig_num)
     {
+#ifdef SIGHUP
     case SIGHUP:
       terminate (_("sighup caught"));
       break;
+#endif
+#ifdef SIGINT
     case SIGINT:
       terminate (_("sigint caught"));
       break;
+#endif
+#ifdef SIGQUIT
     case SIGQUIT:
       terminate (_("sigquit caught"));
       break;
+#endif
+#ifdef SIGABRT
     case SIGABRT:
       terminate (_("sigabrt caught"));
       break;
+#endif
+#ifdef SIGBUS
     case SIGBUS:
       fatal_error (_("sigbus caught"));
       break;
+#endif
+#ifdef SIGSEGV
     case SIGSEGV:
       fatal_error (_("sigsegv caught"));
       break;
+#endif
+#ifdef SIGPIPE
     case SIGPIPE:
       terminate (_("sigpipe caught"));
       break;
+#endif
+#ifdef SIGTERM
     case SIGTERM:
       terminate (_("sigterm caught"));
       break;
+#endif
+#ifdef SIGFPE
     case SIGFPE:
       fatal_error (_("sigfpe caught"));
       break;
+#endif
     default:
       fatal_error (_("unknown signal"));
       break;
     }
 }
 
+#ifdef SIGCHLD
 static RETSIGTYPE
 on_sig_child (int sig_num)
 {
@@ -408,6 +469,7 @@ on_sig_child (int sig_num)
 	break;
     }
 }
+#endif
 
 typedef struct 
 {
diff --git a/app/module_db.c b/app/module_db.c
index fc168c339c..85ba129503 100644
--- a/app/module_db.c
+++ b/app/module_db.c
@@ -18,10 +18,15 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#include <time.h>
 
 #include "appenv.h"
 #include "module_db.h"
@@ -335,16 +340,14 @@ module_info_free (module_info *mod)
 /* helper functions */
 
 
-/* name must be of the form lib*.so */
-/* TODO: need support for WIN32-style dll names.  Maybe this function
- * should live in libgmodule? */
+/* name must be of the form lib*.so (Unix) or *.dll (Win32) */
 static gboolean
 valid_module_name (const char *filename)
 {
   const char *basename;
   int len;
 
-  basename = strrchr (filename, '/');
+  basename = strrchr (filename, G_DIR_SEPARATOR);
   if (basename)
     basename++;
   else
@@ -352,6 +355,7 @@ valid_module_name (const char *filename)
 
   len = strlen (basename);
 
+#ifndef WIN32
   if (len < 3 + 1 + 3)
     return FALSE;
 
@@ -360,6 +364,10 @@ valid_module_name (const char *filename)
 
   if (strcmp (basename + len - 3, ".so"))
     return FALSE;
+#else
+  if (g_strcasecmp (basename + len - 4, ".dll"))
+    return FALSE;
+#endif
 
   return TRUE;
 }
diff --git a/app/paint-funcs/paint-funcs.c b/app/paint-funcs/paint-funcs.c
index 2e7d61bf88..38ed8ea034 100644
--- a/app/paint-funcs/paint-funcs.c
+++ b/app/paint-funcs/paint-funcs.c
@@ -15,10 +15,17 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
 #include "appenv.h"
 #include "gimprc.h"
 #include "paint_funcs.h"
diff --git a/app/paint/gimpclone.c b/app/paint/gimpclone.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/paint/gimpclone.c
+++ b/app/paint/gimpclone.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/paint/gimpink-blob.c b/app/paint/gimpink-blob.c
index 71e960e55b..d62a34b4b2 100644
--- a/app/paint/gimpink-blob.c
+++ b/app/paint/gimpink-blob.c
@@ -31,6 +31,10 @@
 
 #define ROUND(A) floor((A)+0.5)
 
+#ifndef M_PI
+#define M_PI    3.14159265358979323846
+#endif /* M_PI */
+
 static Blob *
 blob_new (int y, int height)
 {
diff --git a/app/paint/gimpsourcecore.c b/app/paint/gimpsourcecore.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/paint/gimpsourcecore.c
+++ b/app/paint/gimpsourcecore.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/paint_funcs.c b/app/paint_funcs.c
index 2e7d61bf88..38ed8ea034 100644
--- a/app/paint_funcs.c
+++ b/app/paint_funcs.c
@@ -15,10 +15,17 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
 
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
 #include "appenv.h"
 #include "gimprc.h"
 #include "paint_funcs.h"
diff --git a/app/palette.c b/app/palette.c
index 5ebaa47c78..ceb9186ad7 100644
--- a/app/palette.c
+++ b/app/palette.c
@@ -15,11 +15,18 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
 #include "appenv.h"
@@ -1257,20 +1264,25 @@ palette_create_entries(gpointer   client_data,
 	  home = g_get_home_dir ();
 	  local_path = g_strdup (palette_path);
 	  first_token = local_path;
-	  token = xstrsep(&first_token, ":");
+	  token = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 
 	  if (token)
 	    {
 	      if (*token == '~')
 		{
-		  path = g_strdup_printf("%s%s", home, token + 1);
+		  if (home)
+		    path = g_strdup_printf("%s%s", home, token + 1);
+		  else
+		    /* Just ignore the ~ if no HOME ??? */
+		    path = g_strdup(token + 1);
 		}
 	      else
 		{
 		  path = g_strdup(token);
 		}
 
-	      entries->filename = g_strdup_printf ("%s/%s", path, palette_name);
+	      entries->filename = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+						   path, palette_name);
 
 	      g_free (path);
 	    }
diff --git a/app/palette_select.c b/app/palette_select.c
index c15ec9d9f9..80c5c58239 100644
--- a/app/palette_select.c
+++ b/app/palette_select.c
@@ -17,13 +17,17 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
-#include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "buildmenu.h"
diff --git a/app/parasitelist.c b/app/parasitelist.c
index 95d9678ce9..11cc0b1c39 100644
--- a/app/parasitelist.c
+++ b/app/parasitelist.c
@@ -15,6 +15,8 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <string.h>
+
 #include "gimpobjectP.h"
 #include "gimpobject.h"
 #include "gimpsignal.h"
diff --git a/app/patterns.c b/app/patterns.c
index 51f0dc5b17..46a2eb353c 100644
--- a/app/patterns.c
+++ b/app/patterns.c
@@ -15,13 +15,21 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
+
 #include "appenv.h"
 #include "colormaps.h"
 #include "datafiles.h"
diff --git a/app/posterize.c b/app/posterize.c
index 9c241dcc3c..6eae632102 100644
--- a/app/posterize.c
+++ b/app/posterize.c
@@ -15,9 +15,17 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "drawable.h"
diff --git a/app/preferences_dialog.c b/app/preferences_dialog.c
index 3d353f49a6..ddf5b0d825 100644
--- a/app/preferences_dialog.c
+++ b/app/preferences_dialog.c
@@ -1,5 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+
 #include "appenv.h"
 #include "about_dialog.h"
 #include "actionarea.h"
diff --git a/app/procedural_db.c b/app/procedural_db.c
index d5eef51f97..1c66be4679 100644
--- a/app/procedural_db.c
+++ b/app/procedural_db.c
@@ -854,7 +854,7 @@ procedural_db_dump (Argument *args)
 
   if (filename)
     {
-      if (! (procedural_db_out = fopen (filename, "wb")))
+      if (! (procedural_db_out = fopen (filename, "w")))
 	success = FALSE;
     }
   else
diff --git a/app/rotate_tool.c b/app/rotate_tool.c
index 00fdf6d972..04dc420776 100644
--- a/app/rotate_tool.c
+++ b/app/rotate_tool.c
@@ -319,7 +319,7 @@ rotate_tool_motion (tool, gdisp_ptr)
 
   /* constrain the angle to 15-degree multiples if ctrl is held down */
   
-  if (transform_core->state & ControlMask)
+  if (transform_core->state & GDK_CONTROL_MASK)
     transform_core->trans_info[ANGLE] = FIFTEEN_DEG * (int) ((transform_core->trans_info[REAL_ANGLE] +
 							      FIFTEEN_DEG / 2.0) /
 							     FIFTEEN_DEG);
diff --git a/app/scale_tool.c b/app/scale_tool.c
index aeef1093d2..386d216be4 100644
--- a/app/scale_tool.c
+++ b/app/scale_tool.c
@@ -310,10 +310,10 @@ scale_tool_motion (tool, gdisp_ptr)
     }
 
   /*  if just the control key is down, affect only the height  */
-  if (transform_core->state & ControlMask && ! (transform_core->state & ShiftMask))
+  if (transform_core->state & GDK_CONTROL_MASK && ! (transform_core->state & GDK_SHIFT_MASK))
     diff_x = 0;
   /*  if just the shift key is down, affect only the width  */
-  else if (transform_core->state & ShiftMask && ! (transform_core->state & ControlMask))
+  else if (transform_core->state & GDK_SHIFT_MASK && ! (transform_core->state & GDK_CONTROL_MASK))
     diff_y = 0;
 
   *x1 += diff_x;
diff --git a/app/temp_buf.c b/app/temp_buf.c
index ca3b6a6268..af4faa1caa 100644
--- a/app/temp_buf.c
+++ b/app/temp_buf.c
@@ -15,12 +15,22 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <string.h>
 #include <sys/stat.h>
+
+#ifdef _MSC_VER
+#include <process.h>		/* For _getpid() */
+#endif
+ 
 #include "appenv.h"
 #include "drawable.h"
 #include "errors.h"
@@ -416,7 +426,8 @@ generate_unique_filename (void)
 {
   pid_t pid;
   pid = getpid ();
-  return g_strdup_printf ("%s/gimp%d.%d", temp_path, (int) pid, swap_index++);
+  return g_strdup_printf ("%s" G_DIR_SEPARATOR_S "gimp%d.%d",
+			  temp_path, (int) pid, swap_index++);
 }
 
 
diff --git a/app/text_tool.c b/app/text_tool.c
index 3863a76823..23d779eb60 100644
--- a/app/text_tool.c
+++ b/app/text_tool.c
@@ -447,6 +447,7 @@ text_gdk_image_to_region (GdkImage    *image,
 			  int          scale,
 			  PixelRegion *textPR)
 {
+  GdkColor black;
   int black_pixel;
   int pixel;
   int value;
@@ -457,7 +458,9 @@ text_gdk_image_to_region (GdkImage    *image,
   unsigned char * data;
 
   scale2 = scale * scale;
-  black_pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  black_pixel = black.pixel;
   data = textPR->data;
 
   for (y = 0, scaley = 0; y < textPR->h; y++, scaley += scale)
@@ -587,8 +590,10 @@ text_render (GImage *gimage,
   gdk_gc_set_font (gc, font);
 
   /*  get black and white pixels for this gdisplay  */
-  black.pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
-  white.pixel = WhitePixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  white.red = white.green = white.blue = 65535;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &white, FALSE, TRUE);
 
   /* Render the text into the pixmap.
    * Since the pixmap may not fully bound the text (because we limit its size)
diff --git a/app/tile_manager.c b/app/tile_manager.c
index 05aa0588c8..f4e56f305a 100644
--- a/app/tile_manager.c
+++ b/app/tile_manager.c
@@ -16,6 +16,8 @@
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
 
+#include <string.h>
+
 #include "tile_cache.h"
 #include "tile_manager.h"
 #include "tile_swap.h"
diff --git a/app/tile_swap.c b/app/tile_swap.c
index fbff8e511e..b94f520f1a 100644
--- a/app/tile_swap.c
+++ b/app/tile_swap.c
@@ -1,13 +1,21 @@
+#include "config.h"
+
 #include <errno.h>
 #include <string.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #ifdef USE_PTHREADS
 #include <pthread.h>
 #endif
 
+#ifdef _MSC_VER
+#include <io.h>
+#endif
+
 #include "libgimp/gimpintl.h"
 
 #define MAX_OPEN_SWAP_FILES  16
@@ -352,7 +360,11 @@ tile_swap_open (SwapFile *swap_file)
       nopen_swap_files -= 1;
     }
 
+#ifndef NATIVE_WIN32
   swap_file->fd = open (swap_file->filename, O_CREAT|O_RDWR, S_IRUSR|S_IWUSR);
+#else
+  swap_file->fd = open (swap_file->filename, O_CREAT|O_RDWR|_O_BINARY, _S_IREAD|_S_IWRITE);
+#endif
   if (swap_file->fd == -1)
     {
       g_message (_("unable to open swap file...BAD THINGS WILL HAPPEN SOON"));
diff --git a/app/tips_dialog.c b/app/tips_dialog.c
index ca89dcaf62..956d7977cd 100644
--- a/app/tips_dialog.c
+++ b/app/tips_dialog.c
@@ -45,9 +45,11 @@ tips_dialog_create ()
   if (tips_count == 0)
     {
       if ((gimp_data_dir = getenv ("GIMP_DATADIR")) != NULL)
-        temp = (char *) g_strdup_printf ("%s/%s", gimp_data_dir, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 gimp_data_dir, TIPS_FILE_NAME);
       else
-        temp = (char *) g_strdup_printf ("%s/%s", DATADIR, TIPS_FILE_NAME);
+        temp = (char *) g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+					 DATADIR, TIPS_FILE_NAME);
       read_tips_file ((char *)temp);
       g_free (temp);
     }
@@ -219,7 +221,7 @@ read_tips_file (char *filename)
   char *tip = NULL;
   char *str = NULL;
 
-  fp = fopen (filename, "rb");
+  fp = fopen (filename, "r");
   if (!fp)
     {
       store_tip (_("Your GIMP tips file appears to be missing!\n"
diff --git a/app/tools/blob.c b/app/tools/blob.c
index 71e960e55b..d62a34b4b2 100644
--- a/app/tools/blob.c
+++ b/app/tools/blob.c
@@ -31,6 +31,10 @@
 
 #define ROUND(A) floor((A)+0.5)
 
+#ifndef M_PI
+#define M_PI    3.14159265358979323846
+#endif /* M_PI */
+
 static Blob *
 blob_new (int y, int height)
 {
diff --git a/app/tools/clone.c b/app/tools/clone.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/tools/clone.c
+++ b/app/tools/clone.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/tools/gimpclonetool.c b/app/tools/gimpclonetool.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/tools/gimpclonetool.c
+++ b/app/tools/gimpclonetool.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/tools/gimpinktool-blob.c b/app/tools/gimpinktool-blob.c
index 71e960e55b..d62a34b4b2 100644
--- a/app/tools/gimpinktool-blob.c
+++ b/app/tools/gimpinktool-blob.c
@@ -31,6 +31,10 @@
 
 #define ROUND(A) floor((A)+0.5)
 
+#ifndef M_PI
+#define M_PI    3.14159265358979323846
+#endif /* M_PI */
+
 static Blob *
 blob_new (int y, int height)
 {
diff --git a/app/tools/gimpposterizetool.c b/app/tools/gimpposterizetool.c
index 9c241dcc3c..6eae632102 100644
--- a/app/tools/gimpposterizetool.c
+++ b/app/tools/gimpposterizetool.c
@@ -15,9 +15,17 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "drawable.h"
diff --git a/app/tools/gimprotatetool.c b/app/tools/gimprotatetool.c
index 00fdf6d972..04dc420776 100644
--- a/app/tools/gimprotatetool.c
+++ b/app/tools/gimprotatetool.c
@@ -319,7 +319,7 @@ rotate_tool_motion (tool, gdisp_ptr)
 
   /* constrain the angle to 15-degree multiples if ctrl is held down */
   
-  if (transform_core->state & ControlMask)
+  if (transform_core->state & GDK_CONTROL_MASK)
     transform_core->trans_info[ANGLE] = FIFTEEN_DEG * (int) ((transform_core->trans_info[REAL_ANGLE] +
 							      FIFTEEN_DEG / 2.0) /
 							     FIFTEEN_DEG);
diff --git a/app/tools/gimpscaletool.c b/app/tools/gimpscaletool.c
index aeef1093d2..386d216be4 100644
--- a/app/tools/gimpscaletool.c
+++ b/app/tools/gimpscaletool.c
@@ -310,10 +310,10 @@ scale_tool_motion (tool, gdisp_ptr)
     }
 
   /*  if just the control key is down, affect only the height  */
-  if (transform_core->state & ControlMask && ! (transform_core->state & ShiftMask))
+  if (transform_core->state & GDK_CONTROL_MASK && ! (transform_core->state & GDK_SHIFT_MASK))
     diff_x = 0;
   /*  if just the shift key is down, affect only the width  */
-  else if (transform_core->state & ShiftMask && ! (transform_core->state & ControlMask))
+  else if (transform_core->state & GDK_SHIFT_MASK && ! (transform_core->state & GDK_CONTROL_MASK))
     diff_y = 0;
 
   *x1 += diff_x;
diff --git a/app/tools/gimpsourcetool.c b/app/tools/gimpsourcetool.c
index 05882eb3a5..0ad87e64dd 100644
--- a/app/tools/gimpsourcetool.c
+++ b/app/tools/gimpsourcetool.c
@@ -235,7 +235,7 @@ clone_paint_func (PaintCore *paint_core,
       y2 = paint_core->lasty;
 
       /*  If the control key is down, move the src target and return */
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  src_x = x1;
 	  src_y = y1;
@@ -269,7 +269,7 @@ clone_paint_func (PaintCore *paint_core,
       break;
 
     case INIT_PAINT :
-      if (paint_core->state & ControlMask)
+      if (paint_core->state & GDK_CONTROL_MASK)
 	{
 	  the_src_gdisp = gdisp;
 	  clone_set_src_drawable(drawable);
diff --git a/app/tools/gimptexttool.c b/app/tools/gimptexttool.c
index 3863a76823..23d779eb60 100644
--- a/app/tools/gimptexttool.c
+++ b/app/tools/gimptexttool.c
@@ -447,6 +447,7 @@ text_gdk_image_to_region (GdkImage    *image,
 			  int          scale,
 			  PixelRegion *textPR)
 {
+  GdkColor black;
   int black_pixel;
   int pixel;
   int value;
@@ -457,7 +458,9 @@ text_gdk_image_to_region (GdkImage    *image,
   unsigned char * data;
 
   scale2 = scale * scale;
-  black_pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  black_pixel = black.pixel;
   data = textPR->data;
 
   for (y = 0, scaley = 0; y < textPR->h; y++, scaley += scale)
@@ -587,8 +590,10 @@ text_render (GImage *gimage,
   gdk_gc_set_font (gc, font);
 
   /*  get black and white pixels for this gdisplay  */
-  black.pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
-  white.pixel = WhitePixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  white.red = white.green = white.blue = 65535;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &white, FALSE, TRUE);
 
   /* Render the text into the pixmap.
    * Since the pixmap may not fully bound the text (because we limit its size)
diff --git a/app/tools/posterize.c b/app/tools/posterize.c
index 9c241dcc3c..6eae632102 100644
--- a/app/tools/posterize.c
+++ b/app/tools/posterize.c
@@ -15,9 +15,17 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
+
+#ifndef HAVE_RINT
+#define rint(x) floor (x + 0.5)
+#endif
+
 #include "appenv.h"
 #include "actionarea.h"
 #include "drawable.h"
diff --git a/app/tools/rotate_tool.c b/app/tools/rotate_tool.c
index 00fdf6d972..04dc420776 100644
--- a/app/tools/rotate_tool.c
+++ b/app/tools/rotate_tool.c
@@ -319,7 +319,7 @@ rotate_tool_motion (tool, gdisp_ptr)
 
   /* constrain the angle to 15-degree multiples if ctrl is held down */
   
-  if (transform_core->state & ControlMask)
+  if (transform_core->state & GDK_CONTROL_MASK)
     transform_core->trans_info[ANGLE] = FIFTEEN_DEG * (int) ((transform_core->trans_info[REAL_ANGLE] +
 							      FIFTEEN_DEG / 2.0) /
 							     FIFTEEN_DEG);
diff --git a/app/tools/scale_tool.c b/app/tools/scale_tool.c
index aeef1093d2..386d216be4 100644
--- a/app/tools/scale_tool.c
+++ b/app/tools/scale_tool.c
@@ -310,10 +310,10 @@ scale_tool_motion (tool, gdisp_ptr)
     }
 
   /*  if just the control key is down, affect only the height  */
-  if (transform_core->state & ControlMask && ! (transform_core->state & ShiftMask))
+  if (transform_core->state & GDK_CONTROL_MASK && ! (transform_core->state & GDK_SHIFT_MASK))
     diff_x = 0;
   /*  if just the shift key is down, affect only the width  */
-  else if (transform_core->state & ShiftMask && ! (transform_core->state & ControlMask))
+  else if (transform_core->state & GDK_SHIFT_MASK && ! (transform_core->state & GDK_CONTROL_MASK))
     diff_y = 0;
 
   *x1 += diff_x;
diff --git a/app/tools/text_tool.c b/app/tools/text_tool.c
index 3863a76823..23d779eb60 100644
--- a/app/tools/text_tool.c
+++ b/app/tools/text_tool.c
@@ -447,6 +447,7 @@ text_gdk_image_to_region (GdkImage    *image,
 			  int          scale,
 			  PixelRegion *textPR)
 {
+  GdkColor black;
   int black_pixel;
   int pixel;
   int value;
@@ -457,7 +458,9 @@ text_gdk_image_to_region (GdkImage    *image,
   unsigned char * data;
 
   scale2 = scale * scale;
-  black_pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  black_pixel = black.pixel;
   data = textPR->data;
 
   for (y = 0, scaley = 0; y < textPR->h; y++, scaley += scale)
@@ -587,8 +590,10 @@ text_render (GImage *gimage,
   gdk_gc_set_font (gc, font);
 
   /*  get black and white pixels for this gdisplay  */
-  black.pixel = BlackPixel (DISPLAY, DefaultScreen (DISPLAY));
-  white.pixel = WhitePixel (DISPLAY, DefaultScreen (DISPLAY));
+  black.red = black.green = black.blue = 0;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &black, FALSE, TRUE);
+  white.red = white.green = white.blue = 65535;
+  gdk_colormap_alloc_color (gdk_colormap_get_system (), &white, FALSE, TRUE);
 
   /* Render the text into the pixmap.
    * Since the pixmap may not fully bound the text (because we limit its size)
diff --git a/app/widgets/gimpgradienteditor.c b/app/widgets/gimpgradienteditor.c
index 0730bdc4f9..787c3fda79 100644
--- a/app/widgets/gimpgradienteditor.c
+++ b/app/widgets/gimpgradienteditor.c
@@ -148,12 +148,15 @@
  * - Add a Gradient brush mode (color changes as you move it).
  */
 
+#include "config.h"
 
 #include <math.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 
 #include "appenv.h"
 #include "colormaps.h"
@@ -168,7 +171,6 @@
 #include "session.h"
 #include "gradient_header.h"
 
-#include "config.h"
 #include "libgimp/gimpintl.h"
 
 /***** Magic numbers *****/
@@ -5970,17 +5972,20 @@ build_user_filename(char *name, char *path_str)
 	home        = g_get_home_dir ();
 	local_path  = g_strdup(path_str);
 	first_token = local_path;
-	token       = xstrsep(&first_token, ":");
+	token       = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 	filename    = NULL;
 
 	if (token) {
 		if (*token == '~') {
+			if (!home)
+				return NULL;
 			path = g_strdup_printf("%s%s", home, token + 1);
 		} else {
 			path = g_strdup(token);
 		} /* else */
 
-		filename = g_strdup_printf("%s/%s", path, name);
+		filename = g_strdup_printf("%s" G_DIR_SEPARATOR_S "%s",
+					   path, name);
 
 		g_free(path);
 	} /* if */
diff --git a/app/widgets/gimppaletteeditor.c b/app/widgets/gimppaletteeditor.c
index 5ebaa47c78..ceb9186ad7 100644
--- a/app/widgets/gimppaletteeditor.c
+++ b/app/widgets/gimppaletteeditor.c
@@ -15,11 +15,18 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
+
+#include "config.h"
+
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
 #include <sys/stat.h>
 #include <sys/types.h>
 #include "appenv.h"
@@ -1257,20 +1264,25 @@ palette_create_entries(gpointer   client_data,
 	  home = g_get_home_dir ();
 	  local_path = g_strdup (palette_path);
 	  first_token = local_path;
-	  token = xstrsep(&first_token, ":");
+	  token = xstrsep(&first_token, G_SEARCHPATH_SEPARATOR_S);
 
 	  if (token)
 	    {
 	      if (*token == '~')
 		{
-		  path = g_strdup_printf("%s%s", home, token + 1);
+		  if (home)
+		    path = g_strdup_printf("%s%s", home, token + 1);
+		  else
+		    /* Just ignore the ~ if no HOME ??? */
+		    path = g_strdup(token + 1);
 		}
 	      else
 		{
 		  path = g_strdup(token);
 		}
 
-	      entries->filename = g_strdup_printf ("%s/%s", path, palette_name);
+	      entries->filename = g_strdup_printf ("%s" G_DIR_SEPARATOR_S "%s",
+						   path, palette_name);
 
 	      g_free (path);
 	    }
diff --git a/app/widgets/gimptoolbox-color-area.c b/app/widgets/gimptoolbox-color-area.c
index ae86ca4355..cfdec2506d 100644
--- a/app/widgets/gimptoolbox-color-area.c
+++ b/app/widgets/gimptoolbox-color-area.c
@@ -17,6 +17,7 @@
  */
 
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "color_area.h"
 #include "color_notebook.h"
diff --git a/app/xcf.c b/app/xcf.c
index ef85f3ad67..3489c0b700 100644
--- a/app/xcf.c
+++ b/app/xcf.c
@@ -1,11 +1,17 @@
+#include "config.h"
+
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <errno.h>
 
 #include <glib.h>
diff --git a/app/xcf/xcf.c b/app/xcf/xcf.c
index ef85f3ad67..3489c0b700 100644
--- a/app/xcf/xcf.c
+++ b/app/xcf/xcf.c
@@ -1,11 +1,17 @@
+#include "config.h"
+
 #include <errno.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#ifdef HAVE_SYS_PARAM_H
 #include <sys/param.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <errno.h>
 
 #include <glib.h>
diff --git a/libgimpbase/gimpdatafiles.c b/libgimpbase/gimpdatafiles.c
index da558448b9..74aba57d30 100644
--- a/libgimpbase/gimpdatafiles.c
+++ b/libgimpbase/gimpdatafiles.c
@@ -18,15 +18,29 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  */
-
+#include "config.h"
 
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/stat.h>
+#ifdef HAVE_UNISTD_H
 #include <unistd.h>
+#endif
 #include <sys/types.h>
+#ifdef HAVE_DIRENT_H
 #include <dirent.h>
+#endif
+
+#ifdef _MSC_VER
+#ifndef S_ISDIR
+#define S_ISDIR(m) (((m) & _S_IFMT) == _S_IFDIR)
+#define S_ISREG(m) (((m) & _S_IFMT) == _S_IFREG)
+#endif
+#ifndef S_IXUSR
+#define S_IXUSR _S_IEXEC
+#endif
+#endif
 
 #include <glib.h>
 #include "datafiles.h"
@@ -70,7 +84,7 @@ datafiles_read_directories (char *path_str,
 
   next_token = local_path;
 
-  token = xstrsep(&next_token, ":");
+  token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
 
   while (token)
     {
@@ -90,8 +104,8 @@ datafiles_read_directories (char *path_str,
 
       if (!err && S_ISDIR(filestat.st_mode))
 	{
-	  if (path[strlen(path) - 1] != '/')
-	    strcat(path, "/");
+	  if (path[strlen(path) - 1] != G_DIR_SEPARATOR)
+	    strcat(path, G_DIR_SEPARATOR_S);
 
 	  /* Open directory */
 	  dir = opendir(path);
@@ -124,7 +138,7 @@ datafiles_read_directories (char *path_str,
 
       g_free(path);
 
-      token = xstrsep(&next_token, ":");
+      token = xstrsep(&next_token, G_SEARCHPATH_SEPARATOR_S);
     } /* while */
 
   g_free(local_path);
diff --git a/libgimpwidgets/gimpcolorselect.c b/libgimpwidgets/gimpcolorselect.c
index eaee373af3..757daf9db5 100644
--- a/libgimpwidgets/gimpcolorselect.c
+++ b/libgimpwidgets/gimpcolorselect.c
@@ -17,6 +17,7 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include "appenv.h"
 #include "actionarea.h"
 #include "color_select.h"