diff --git a/.gitattributes b/.gitattributes
index c6d21e2..f7e650b 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1 +1,2 @@
 /src/stb_ds.h linguist-generated
+/src/stb_image.h linguist-generated
diff --git a/GNUmakefile b/GNUmakefile
index 702afd3..57bf9e3 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -7,7 +7,7 @@ CFLAGS = -Wall -Wextra -Iinclude
 LDFLAGS =
 LIBS =
 
-L_CFLAGS = $(CFLAGS) -fPIC -D_MILSKO -DHAVE_CONFIG_H
+L_CFLAGS = $(CFLAGS) -fPIC -D_MILSKO
 L_LDFLAGS = $(LDFLAGS)
 L_LIBS = $(LIBS)
 
@@ -16,7 +16,7 @@ E_LDFLAGS = $(LDFLAGS) -Lsrc
 E_LIBS = $(LIBS) -lMw
 
 L_OBJS = src/ds.o src/core.o src/default.o src/draw.o src/lowlevel.o src/font.o src/image.o
-L_OBJS += src/window.o src/button.o src/opengl.o src/frame.o src/vulkan.o
+L_OBJS += src/window.o src/button.o src/frame.o
 
 ifeq ($(TARGET),NetBSD)
 CFLAGS += -I/usr/X11R7/include -I/usr/pkg/include
@@ -24,6 +24,7 @@ LDFLAGS += -L/usr/X11R7/lib -L/usr/pkg/lib -Wl,-R/usr/X11R7/lib -Wl,-R/usr/pkg/l
 UNIX = 1
 else ifeq ($(TARGET),Linux)
 UNIX = 1
+VULKAN = 1
 else ifeq ($(TARGET),Windows)
 WINDOWS = 1
 else
@@ -33,7 +34,7 @@ endif
 ifeq ($(UNIX),1)
 L_CFLAGS += -DUSE_X11
 L_OBJS += src/x11.o
-L_LIBS += -lX11 -lXrender -lXext -lGL
+L_LIBS += -lX11 -lXrender -lXext
 
 GL = -lGL
 
@@ -41,19 +42,39 @@ E_LIBS += -lm
 
 SO = .so
 EXEC =
+
+OPENGL = 1
 else ifeq ($(WINDOWS),1)
 L_CFLAGS += -DUSE_GDI
 L_LDFLAGS += -Wl,--out-implib,src/libMw.lib -static-libgcc
 L_OBJS += src/gdi.o
-L_LIBS += -lgdi32 -lopengl32
+L_LIBS += -lgdi32
 
 GL = -lopengl32
 
 SO = .dll
 EXEC = .exe
+
+OPENGL = 1
 endif
 
-EXAMPLES = examples/example$(EXEC) examples/rotate$(EXEC) examples/opengl$(EXEC) examples/image$(EXEC) examples/vulkan$(EXEC)
+EXAMPLES = examples/example$(EXEC) examples/rotate$(EXEC) examples/image$(EXEC)
+
+ifeq ($(OPENGL),1)
+L_OBJS += src/opengl.o
+EXAMPLES += examples/opengl$(EXEC)
+
+ifeq ($(UNIX),1)
+L_LIBS += -lGL
+else ifeq ($(WINDOWS),1)
+L_LIBS += -lopengl32
+endif
+endif
+
+ifeq ($(VULKAN),1)
+L_OBJS += src/vulkan.o
+EXAMPLES += examples/vulkan$(EXEC)
+endif
 
 .PHONY: all format clean lib examples
 
@@ -81,4 +102,4 @@ examples/%.o: examples/%.c
 	$(CC) $(E_CFLAGS) -c -o $@ $<
 
 clean:
-	rm -f src/*.dll src/*.so src/*.a src/*.lib */*.o */*/*.o examples/*.exe $(EXAMPLES)
+	rm -f src/*.dll src/*.so src/*.a src/*.lib */*.o */*/*.o examples/*.exe $(EXAMPLES) examples/opengl examples/vulkan
diff --git a/examples/opengl.c b/examples/opengl.c
index b080a9c..52ba707 100644
--- a/examples/opengl.c
+++ b/examples/opengl.c
@@ -1,5 +1,6 @@
 /* $Id$ */
 #include <Mw/Milsko.h>
+#include <Mw/OpenGL.h>
 
 #include <GL/gl.h>
 
diff --git a/include/Mw/Milsko.h b/include/Mw/Milsko.h
index 21cd3b4..71096be 100644
--- a/include/Mw/Milsko.h
+++ b/include/Mw/Milsko.h
@@ -19,6 +19,5 @@
 #include <Mw/Window.h>
 #include <Mw/Button.h>
 #include <Mw/Frame.h>
-#include <Mw/OpenGL.h>
 
 #endif
diff --git a/src/opengl.c b/src/opengl.c
index dc5b0ec..b63c3b3 100644
--- a/src/opengl.c
+++ b/src/opengl.c
@@ -1,5 +1,6 @@
 /* $Id$ */
 #include <Mw/Milsko.h>
+#include <Mw/OpenGL.h>
 
 #ifdef _WIN32
 /* nothing */
diff --git a/src/vulkan.c b/src/vulkan.c
index 650cb45..40621d2 100644
--- a/src/vulkan.c
+++ b/src/vulkan.c
@@ -1,14 +1,6 @@
 /* $Id$ */
-#include "Mw/Vulkan.h"
-#include "Mw/TypeDefs.h"
 #include <Mw/Milsko.h>
-#include <Mw/TypeDefs.h>
-
-#include <X11/Xlib.h>
-#include <stdio.h>
-#include <stdlib.h>
-
-#include <string.h>
+#include <Mw/Vulkan.h>
 
 #ifdef _WIN32
 #define VK_USE_PLATFORM_WIN32_KHR 1