diff --git a/Makefile b/Makefile
index 3456087bea..75e736c14e 100644
--- a/Makefile
+++ b/Makefile
@@ -2,8 +2,10 @@ CC = gcc
 CP = cp
 
 BINARY = f
+IMAGE = factor.image
 BUNDLE = Factor.app
 BUNDLE_BINARY = $(BUNDLE)/Contents/MacOS/Factor
+BUNDLE_IMAGE = $(BUNDLE)/Contents/factor.image
 
 ifdef DEBUG
 	DEFAULT_CFLAGS = -g
@@ -92,7 +94,10 @@ macosx:
 		CFLAGS="$(DEFAULT_CFLAGS)" \
 		LIBS="$(DEFAULT_LIBS) -framework Cocoa -framework OpenGL" \
 		MACOSX=y
+
+macosx.app:
 	$(CP) $(BINARY) $(BUNDLE_BINARY)
+	$(CP) $(IMAGE) $(BUNDLE_IMAGE)
 
 linux linux-x86 linux-amd64:
 	$(MAKE) $(BINARY) \
diff --git a/native/factor.c b/native/factor.c
index a2f2a27de9..164e0a9466 100644
--- a/native/factor.c
+++ b/native/factor.c
@@ -37,9 +37,24 @@ INLINE bool factor_arg(const char* str, const char* arg, CELL* value)
 		return false;
 }
 
+void usage(void)
+{
+	printf("Usage: factor <image file> [ parameters ... ]\n");
+	printf("Runtime options -- n is a number:\n");
+	printf(" +Dn   Data stack size, kilobytes\n");
+	printf(" +Cn   Call stack size, kilobytes\n");
+	printf(" +Gn   Number of generations, must be >= 2\n");
+	printf(" +Yn   Size of n-1 youngest generations, megabytes\n");
+	printf(" +An   Size of tenured and semi-spaces, megabytes\n");
+	printf(" +Xn   Code heap size, megabytes\n");
+	printf("Other options are handled by the Factor library.\n");
+	printf("See the documentation for details.\n");
+	printf("Send bug reports to Slava Pestov <slava@factorcode.org>.\n");
+}
+
 int main(int argc, char** argv)
 {
-	char *image;
+	char *image = NULL;
 	CELL ds_size = 128;
 	CELL cs_size = 128;
 	CELL generations = 2;
@@ -50,21 +65,7 @@ int main(int argc, char** argv)
 	CELL args;
 	CELL i;
 
-	if(argc == 1)
-	{
-		printf("Usage: factor <image file> [ parameters ... ]\n");
-		printf("Runtime options -- n is a number:\n");
-		printf(" +Dn   Data stack size, kilobytes\n");
-		printf(" +Cn   Call stack size, kilobytes\n");
-		printf(" +Gn   Number of generations, must be >= 2\n");
-		printf(" +Yn   Size of n-1 youngest generations, megabytes\n");
-		printf(" +An   Size of tenured and semi-spaces, megabytes\n");
-		printf(" +Xn   Code heap size, megabytes\n");
-		printf("Other options are handled by the Factor library.\n");
-		printf("See the documentation for details.\n");
-		printf("Send bug reports to Slava Pestov <slava@factorcode.org>.\n");
-		return 1;
-	}
+	early_init();
 
 	for(i = 1; i < argc; i++)
 	{
@@ -78,11 +79,16 @@ int main(int argc, char** argv)
 		if(strncmp(argv[i],"+",1) == 0)
 		{
 			printf("Unknown option: %s\n",argv[i]);
+			usage();
 			return 1;
 		}
+
+		if(strncmp(argv[i],"-",1) != 0 && image == NULL)
+			image = argv[1];
 	}
 
-	image = argv[1];
+	if(image == NULL)
+		image = default_image_path();
 
 	init_factor(image,
 		ds_size * 1024,
@@ -94,7 +100,7 @@ int main(int argc, char** argv)
 		literal_size * 1024);
 
 	args = F;
-	while(--argc != 1)
+	while(--argc > 1)
 	{
 		args = cons(tag_object(from_c_string(argv[argc])),args);
 	}
diff --git a/native/factor.h b/native/factor.h
index 32851b83d3..5e46d5319a 100644
--- a/native/factor.h
+++ b/native/factor.h
@@ -141,4 +141,10 @@ CELL executing;
 #include "dll.h"
 #include "wrapper.h"
 
+void usage(void);
+
+void early_init(void);
+
+const char *default_image_path(void);
+
 #endif /* __FACTOR_H__ */
diff --git a/native/image.c b/native/image.c
index 1e033ef26f..903f9edf39 100644
--- a/native/image.c
+++ b/native/image.c
@@ -20,11 +20,16 @@ void load_image(char* filename, int literal_table)
 	HEADER h;
 	HEADER_2 ext_h;
 
-	printf("Loading %s...",filename);
-
 	file = fopen(filename,"rb");
 	if(file == NULL)
-		fatal_error("Cannot open image for reading",errno);
+	{
+		fprintf(stderr,"Cannot open image file: %s\n",filename);
+		fprintf(stderr,"%s\n",strerror(errno));
+		usage();
+		exit(1);
+	}
+
+	printf("Loading %s...",filename);
 
 	/* read header */
 	{
diff --git a/native/macosx/run.m b/native/macosx/run.m
index 3fadf44a25..7851e21dfd 100644
--- a/native/macosx/run.m
+++ b/native/macosx/run.m
@@ -1,7 +1,10 @@
-/* Cocoa exception handling for Mac OS X */
+/* Cocoa exception handling and default image path for Mac OS X */
 
 #include "../factor.h"
+#import "Foundation/NSAutoreleasePool.h"
+#import "Foundation/NSBundle.h"
 #import "Foundation/NSException.h"
+#import "Foundation/NSString.h"
 
 /* This code is convoluted because Cocoa places restrictions on longjmp and
 exception handling. In particular, a longjmp can never cross an NS_DURING,
@@ -20,7 +23,7 @@ NS_DURING
 		{
 			CELL e = error;
 			error = F;
-			general_error(ERROR_OBJECTIVE_C,error,true);
+			general_error(ERROR_OBJECTIVE_C,e,true);
 		}
 
 		run();
@@ -31,3 +34,15 @@ NS_ENDHANDLER
 	}
 }
 
+void early_init(void)
+{
+	[[NSAutoreleasePool alloc] init];
+}
+
+const char *default_image_path(void)
+{
+	NSBundle *bundle = [NSBundle mainBundle];
+	NSString *path = [bundle bundlePath];
+	NSString *image = [path stringByAppendingString:@"/Contents/factor.image"];
+	return [image cString];
+}
diff --git a/native/unix/run.c b/native/unix/run.c
index e7cc648124..2d65e03ac0 100644
--- a/native/unix/run.c
+++ b/native/unix/run.c
@@ -1,7 +1,13 @@
 #include "../factor.h"
 
-void platform_run()
+void platform_run(void)
 {
 	run_toplevel();
 }
 
+void early_init(void) {}
+
+char *default_image_path()
+{
+	return "factor.image";
+}
diff --git a/native/win32/run.c b/native/win32/run.c
index caf93c49aa..7369607a37 100644
--- a/native/win32/run.c
+++ b/native/win32/run.c
@@ -24,7 +24,14 @@ static long exception_handler(void *rec, void *frame, void *ctx, void *dispatch)
 	signal_error(SIGSEGV);
 }
 
-void platform_run ()
+void platform_run(void)
 {
 	seh_call(run_toplevel, exception_handler);
 }
+
+void early_init(void) {}
+
+const char *default_image_path()
+{
+	return "factor.image";
+}