diff --git a/engine/bind/v4k.lua b/engine/bind/v4k.lua
index cfbb8ce..333df75 100644
--- a/engine/bind/v4k.lua
+++ b/engine/bind/v4k.lua
@@ -2736,6 +2736,7 @@ int u_coefficients_sh;
  void        tty_attach();
  void        tty_detach();
  const char* app_exec(const char *command);
+ void 		app_spawn(const char *command);
  int         app_cores();
  int         app_battery();
  const char* app_name();
diff --git a/engine/joint/v4k.h b/engine/joint/v4k.h
index e60cec5..1560d29 100644
--- a/engine/joint/v4k.h
+++ b/engine/joint/v4k.h
@@ -17301,6 +17301,7 @@ API void        tty_attach();
 API void        tty_detach();
 
 API const char* app_exec(const char *command); // returns ("%15d %s", retcode, output_last_line)
+API void 		app_spawn(const char *command);
 API int         app_cores();
 API int         app_battery(); /// return battery level [1..100]. also positive if charging (+), negative if discharging (-), and 0 if no battery is present.
 
@@ -345560,6 +345561,13 @@ const char * app_exec( const char *cmd ) {
     return snprintf(output, 16, "%-15d", rc), buf[-1] = ' ', output;
 }
 
+void app_spawn( const char *cmd ) {
+    if( !cmd[0] ) return "0               ";
+    cmd = file_normalize(cmd);
+
+    system(cmd);
+}
+
 #if is(osx)
 #include <execinfo.h> // backtrace, backtrace_symbols
 #include <dlfcn.h>    // dladdr, Dl_info
@@ -346959,6 +346967,7 @@ int ui_show(const char *panel_or_window_title, int enabled) {
 }
 int ui_dims(const char *panel_or_window_title, float width, float height) {
     nk_window_set_size(ui_ctx, panel_or_window_title, (struct nk_vec2){width, height});
+    return 0;
 }
 vec2 ui_get_dims() {
     return (vec2){nk_window_get_width(ui_ctx), nk_window_get_height(ui_ctx)};
diff --git a/engine/split/v4k_system.c b/engine/split/v4k_system.c
index 3d77c19..dc9208e 100644
--- a/engine/split/v4k_system.c
+++ b/engine/split/v4k_system.c
@@ -106,6 +106,13 @@ const char * app_exec( const char *cmd ) {
     return snprintf(output, 16, "%-15d", rc), buf[-1] = ' ', output;
 }
 
+void app_spawn( const char *cmd ) {
+    if( !cmd[0] ) return "0               ";
+    cmd = file_normalize(cmd);
+
+    system(cmd);
+}
+
 #if is(osx)
 #include <execinfo.h> // backtrace, backtrace_symbols
 #include <dlfcn.h>    // dladdr, Dl_info
diff --git a/engine/split/v4k_system.h b/engine/split/v4k_system.h
index 9f3f326..0fb8197 100644
--- a/engine/split/v4k_system.h
+++ b/engine/split/v4k_system.h
@@ -22,6 +22,7 @@ API void        tty_attach();
 API void        tty_detach();
 
 API const char* app_exec(const char *command); // returns ("%15d %s", retcode, output_last_line)
+API void 		app_spawn(const char *command);
 API int         app_cores();
 API int         app_battery(); /// return battery level [1..100]. also positive if charging (+), negative if discharging (-), and 0 if no battery is present.
 
diff --git a/engine/split/v4k_ui.c b/engine/split/v4k_ui.c
index 8f1b2ac..4d5fd80 100644
--- a/engine/split/v4k_ui.c
+++ b/engine/split/v4k_ui.c
@@ -436,6 +436,7 @@ int ui_show(const char *panel_or_window_title, int enabled) {
 }
 int ui_dims(const char *panel_or_window_title, float width, float height) {
     nk_window_set_size(ui_ctx, panel_or_window_title, (struct nk_vec2){width, height});
+    return 0;
 }
 vec2 ui_get_dims() {
     return (vec2){nk_window_get_width(ui_ctx), nk_window_get_height(ui_ctx)};
diff --git a/engine/v4k.c b/engine/v4k.c
index 89843fe..43a1fa9 100644
--- a/engine/v4k.c
+++ b/engine/v4k.c
@@ -16256,6 +16256,13 @@ const char * app_exec( const char *cmd ) {
     return snprintf(output, 16, "%-15d", rc), buf[-1] = ' ', output;
 }
 
+void app_spawn( const char *cmd ) {
+    if( !cmd[0] ) return "0               ";
+    cmd = file_normalize(cmd);
+
+    system(cmd);
+}
+
 #if is(osx)
 #include <execinfo.h> // backtrace, backtrace_symbols
 #include <dlfcn.h>    // dladdr, Dl_info
@@ -17655,6 +17662,7 @@ int ui_show(const char *panel_or_window_title, int enabled) {
 }
 int ui_dims(const char *panel_or_window_title, float width, float height) {
     nk_window_set_size(ui_ctx, panel_or_window_title, (struct nk_vec2){width, height});
+    return 0;
 }
 vec2 ui_get_dims() {
     return (vec2){nk_window_get_width(ui_ctx), nk_window_get_height(ui_ctx)};
diff --git a/engine/v4k.h b/engine/v4k.h
index dcce828..63332b4 100644
--- a/engine/v4k.h
+++ b/engine/v4k.h
@@ -3384,6 +3384,7 @@ API void        tty_attach();
 API void        tty_detach();
 
 API const char* app_exec(const char *command); // returns ("%15d %s", retcode, output_last_line)
+API void 		app_spawn(const char *command);
 API int         app_cores();
 API int         app_battery(); /// return battery level [1..100]. also positive if charging (+), negative if discharging (-), and 0 if no battery is present.
 
diff --git a/workbench/workbench.c b/workbench/workbench.c
index 4cb2218..801ad38 100644
--- a/workbench/workbench.c
+++ b/workbench/workbench.c
@@ -44,7 +44,7 @@ void register_extensions() {
 }
 
 void edit_asset(char *fname) {
-    app_exec(va("%s %s", ifdef(win32, "start", ifdef(osx, "open", "xdg-open")), fname));
+    app_spawn(va("%s \"\" \"%s\"", ifdef(win32, "start", ifdef(osx, "open", "xdg-open")), fname));
 }
 
 void load_asset(const char *fname) {
@@ -81,22 +81,21 @@ int main() {
     load_editors();
     register_extensions();
 
-    #if 1
+    #if 0
     load_asset("demos/art/shadertoys/!default.fs");
     load_asset("demos/art/fx/fxDithering.fs");
 
     #endif
 
     while( window_swap() && !input(KEY_ESC) ) {
-        static int wb_enabled = 1;
-        if (ui_window("Workbench", &wb_enabled)) {
+        if (ui_panel("Workbench", PANEL_OPEN)) {
             static const char *file;
             static bool show_browser = 1;
             if( ui_browse(&file, &show_browser) ) {
                 load_asset(file);
                 show_browser = 1;
             }
-            ui_window_end();
+            ui_panel_end();
         }
 
         for (int i=0; i<array_count(assets); i++) {