diff --git a/dep/osdialog/Makefile_test_zenity b/dep/osdialog/Makefile_test_zenity
new file mode 100644
index 00000000..2a4e6a0e
--- /dev/null
+++ b/dep/osdialog/Makefile_test_zenity
@@ -0,0 +1,25 @@
+
+CC=gcc
+CPP=g++
+
+TARGET=test_zenity
+
+ALL_OBJ= \
+	osdialog_zenity.o \
+	test_zenity.o
+
+CPPFLAGS= -Wall
+CFLAGS= -Wall
+
+.cpp.o:
+	$(CPP) $(CPPFLAGS) -c $< -o $@ 
+
+.c.o:
+	$(CC) $(CFLAGS) -c $< -o $@ 
+
+test_zenity: $(ALL_OBJ)
+	$(CPP) -o $(TARGET) $(ALL_OBJ)
+
+.PHONY:
+clean:
+	rm -f $(TARGET) $(ALL_OBJ)
diff --git a/dep/osdialog/osdialog_zenity.cpp b/dep/osdialog/osdialog_zenity.cpp
new file mode 100644
index 00000000..99a267b4
--- /dev/null
+++ b/dep/osdialog/osdialog_zenity.cpp
@@ -0,0 +1,281 @@
+//
+//    file: osdialog_zenity.cpp
+//  author: bsp
+// license: CC0 (public domain)
+// created: 24May2019
+// changed:
+//
+
+// Enable / disable debug messages
+#define Dprintf if(1);else printf
+
+#include <string>
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "osdialog.h"
+
+#define ZENITY_CMD "/usr/bin/zenity"
+#define DLG_TITLE  "Rack"
+
+#define MAX_BUF_SIZE  (65536)
+#ifndef NULL
+#define NULL ((void*)0)
+#endif // NULL
+
+
+/* @function psystem,String cmd,char access,String buf:int
+Invoke system command
+
+@arg cmd Command line
+@arg buf Input resp. output buffer
+@return Number of bytes read resp. written
+*/
+static int loc_psystem(const char *_cmd, std::string &_buf) { 
+   int r = 0;
+
+   Dprintf("osdialog_zenity: loc_psystem(cmd=\'%s\')\n", _cmd);
+
+   char *buf = new char[MAX_BUF_SIZE];
+   _buf.clear();
+   if(NULL != buf)
+   {
+      FILE *f; 
+#ifdef _MSC_VER
+      f=::_popen(_cmd, "r"); 
+#else 
+      f=::popen(_cmd, "r"); 
+#endif 
+      int fe = ferror(f); 
+      if(NULL != f) 
+      { 
+         r = (int)::fread(buf, 1, MAX_BUF_SIZE-1, f); 
+         fe = ferror(f); 
+         if( ((unsigned int)r+1) < (MAX_BUF_SIZE-1) )
+         {
+            buf[r] = 0;
+            _buf = buf;
+         }
+#ifdef _MSC_VER
+         ::_pclose(f); 
+#else 
+         ::pclose(f); 
+#endif 
+      } 
+      if( (0 != fe) || (NULL == f) ) 
+      { 
+         printf("[---] osdialog_zenity: psystem(%s, \'r\', ..) failed with error code %i.\n", 
+                _cmd,
+                fe 
+                ); 
+      } 
+
+      delete [] buf;
+   } // if buf
+
+   return r; 
+} 
+
+static int loc_system(const char *_cmd) { 
+   Dprintf("osdialog_zenity: loc_system(cmd=\'%s\')\n", _cmd);
+   int r = ::system(_cmd); 
+   return r;
+} 
+
+
+extern "C" {
+int osdialog_message(osdialog_message_level level, osdialog_message_buttons buttons, const char *message) {
+   int r = 0;
+
+   std::string cmd = ZENITY_CMD;
+
+   if(OSDIALOG_OK == buttons)
+   {
+      switch(level)
+      {
+         default:
+         case OSDIALOG_INFO:
+            cmd.append(" --info");
+            break;
+
+         case OSDIALOG_WARNING:
+            cmd.append(" --warning");
+            break;
+
+         case OSDIALOG_ERROR:
+            cmd.append(" --error");
+            break;
+      }
+   }
+   else
+   {
+      cmd.append(" --question");
+
+      switch(level)
+      {
+         default:
+         case OSDIALOG_INFO:
+            cmd.append(" --icon-name \"dialog-information\"");
+            break;
+
+         case OSDIALOG_WARNING:
+            cmd.append(" --icon-name \"dialog-warning\"");
+            break;
+
+         case OSDIALOG_ERROR:
+            cmd.append(" --icon-name \"dialog-error\"");
+            break;
+      }
+   }
+
+   cmd.append(" --text=\"");
+   cmd.append(message);
+   cmd.append("\"");
+
+   cmd.append(" --title \"" DLG_TITLE "\"");
+
+   r = loc_system(cmd.c_str());
+   r = (256 == r) ? 0 : 1;
+
+   return r;
+}
+
+char *osdialog_file(osdialog_file_action action, const char *path, const char *filename, osdialog_filters *filters) {
+   char *r = NULL;
+
+   std::string cmd = ZENITY_CMD;
+
+   cmd.append(" --file-selection");
+
+   switch(action)
+   {
+      default:
+      case OSDIALOG_OPEN:
+         break;
+
+      case OSDIALOG_OPEN_DIR:
+         cmd.append("  --directory");
+         break;
+
+      case OSDIALOG_SAVE:
+         cmd.append("  --save --confirm-overwrite");
+         break;
+   }
+
+   osdialog_filters *cf = filters;
+   while(NULL != cf)
+   {
+      cmd.append(" --file-filter \"");
+      cmd.append(cf->name);
+      cmd.append(" (");
+      osdialog_filter_patterns *cp = cf->patterns;
+      while(NULL != cp)
+      {
+         if(cp != cf->patterns)
+            cmd.append(", ");
+         cmd.append(cp->pattern);
+         cp = cp->next;
+      }
+      cmd.append(") | ");
+      
+      cp = cf->patterns;
+      while(NULL != cp)
+      {
+         cmd.append("*.");
+         cmd.append(cp->pattern);
+         cp = cp->next;
+         if(NULL != cp)
+            cmd.append(" ");
+      }
+
+      cmd.append("\"");
+      cf = cf->next;
+   }
+
+   cmd.append(" --filename \"");
+   if(NULL != path)
+   {
+      cmd.append(path);
+      cmd.append("/");
+   }
+   if(NULL != filename)
+   {
+      cmd.append(filename);
+   }
+   cmd.append("\"");
+
+   cmd.append(" --title \"" DLG_TITLE "\"");
+
+   std::string buf;
+   if(loc_psystem(cmd.c_str(), buf) > 1)
+   {
+      Dprintf("osdialog_zenity: file selection returned buf=\'%s\'\n", buf.c_str());
+      size_t bufSize = buf.size() - 1;
+
+      r = (char*)malloc((bufSize + 1) * sizeof(char));
+      if(NULL != r)
+      {
+         memcpy((void*)r, (void*)buf.c_str(), bufSize);
+         r[bufSize] = 0;
+      }
+   }
+
+   return r;
+}
+
+int osdialog_color_picker(osdialog_color *color, int opacity) {
+   int r = 0;
+
+   (void)opacity;  // 1=enable opacity slider
+
+   std::string cmd = ZENITY_CMD;
+
+   cmd.append(" --color-selection");
+
+   if(NULL != color)
+   {
+      cmd.append(" --color \"rgba(");
+      char buf[10];
+      sprintf(buf, "%d,%d,%d,%f", color->r, color->g, color->b, color->a / 255.0f);
+      cmd.append(buf);
+      cmd.append(")\"");
+   }
+
+   cmd.append(" --title \"" DLG_TITLE "\"");
+#if 0
+   cmd.append(" --show-palette");
+#endif
+
+   std::string buf;
+   if(loc_psystem(cmd.c_str(), buf) > 1)
+   {
+      Dprintf("osdialog_zenity: color selection returned buf=\'%s\'\n", buf.c_str());
+      {
+         unsigned int r = 0u, g = 0u, b = 0u;
+         float a = 1.0f;
+         if(NULL != strstr(buf.c_str(), "rgba("))
+         {
+            // (note) not supported by Zenity 3.22.0 (latest version as of 24May2019)
+            sscanf(buf.c_str(), "rgba(%u,%u,%u,%f)", &r, &g, &b, &a);
+            color->r = (unsigned char)(r);
+            color->g = (unsigned char)(g);
+            color->b = (unsigned char)(b);
+            color->a = (unsigned char)(a * 255u);
+         }
+         else
+         {
+            sscanf(buf.c_str(), "rgb(%u,%u,%u)", &r, &g, &b);
+            color->r = (unsigned char)(r);
+            color->g = (unsigned char)(g);
+            color->b = (unsigned char)(b);
+         }
+      }
+      r = 1;
+   }
+
+   return r;
+}
+} // extern "C"
+
diff --git a/dep/osdialog/test_zenity.c b/dep/osdialog/test_zenity.c
new file mode 100644
index 00000000..fd98ecaf
--- /dev/null
+++ b/dep/osdialog/test_zenity.c
@@ -0,0 +1,142 @@
+//
+//    file: test_zenity.c
+//  author: bsp
+// license: CC0 (public domain)
+// created: 24May2019
+// changed:
+//
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "osdialog.h"
+
+int main(int argc, char**argv) {
+   int r = 0;
+   char *name = NULL;
+
+   if(1 == argc)
+   {
+      // Test message dialogs (ok)
+      r = osdialog_message(OSDIALOG_INFO, OSDIALOG_OK, "This is an info message.");
+      printf("info dialog returned r=%d\n", r);
+
+      r = osdialog_message(OSDIALOG_WARNING, OSDIALOG_OK, "This is a warning message.");
+      printf("warning dialog returned r=%d\n", r);
+
+      r = osdialog_message(OSDIALOG_ERROR, OSDIALOG_OK, "This is an error message.");
+      printf("error dialog returned r=%d\n", r);
+
+      // Test message dialogs (ok / cancel / yes / no)
+      r = osdialog_message(OSDIALOG_INFO, OSDIALOG_YES_NO, "This is an info message.");
+      printf("info dialog returned r=%d\n", r);
+
+      r = osdialog_message(OSDIALOG_WARNING, OSDIALOG_OK_CANCEL, "This is a warning message.");
+      printf("warning dialog returned r=%d\n", r);
+
+      r = osdialog_message(OSDIALOG_ERROR, OSDIALOG_YES_NO, "This is an error message.");
+      printf("error dialog returned r=%d\n", r);
+   }
+
+   // Test file dialogs
+   if(argc <= 2)
+   {
+      osdialog_filter_patterns patternsMP3 = {
+         "mp3",
+         NULL
+      };
+      osdialog_filter_patterns patternsFLAC = {
+         "flac",
+         &patternsMP3
+      };
+      osdialog_filter_patterns patternsWAV = {
+         "wav",
+         &patternsFLAC
+      };
+      osdialog_filters filterAudio = {
+         "Audio Files",
+         &patternsWAV,
+         NULL
+      };
+
+      osdialog_filter_patterns patternsAVI = {
+         "avi",
+         NULL
+      };
+      osdialog_filter_patterns patternsMP4 = {
+         "mp4",
+         &patternsAVI
+      };
+      osdialog_filter_patterns patternsMKV = {
+         "mkv",
+         &patternsMP4
+      };
+      osdialog_filters filterVideo = {
+         "Video Files",
+         &patternsMKV,
+         &filterAudio
+      };
+
+      // File selection (open)
+      {
+         name = osdialog_file(OSDIALOG_OPEN, "/tmp/"/*path*/, "myfile", &filterVideo);
+         if(NULL != name)
+         {
+            printf("selected file (open) is \"%s\"\n", name);
+            free(name);
+         }
+         else
+         {
+            printf("file OSDIALOG_OPEN was canceled.\n");
+         }
+      }
+
+      // Directory selection
+      {
+         name = osdialog_file(OSDIALOG_OPEN_DIR, "/tmp/"/*path*/, "myfile", NULL/*filters*/);
+         if(NULL != name)
+         {
+            printf("selected directory is \"%s\"\n", name);
+            free(name);
+         }
+         else
+         {
+            printf("file OSDIALOG_OPEN_DIR was canceled.\n");
+         }
+      }
+
+      // File selection (save)
+      {
+         name = osdialog_file(OSDIALOG_SAVE, "/tmp/"/*path*/, "myfile", &filterVideo);
+         if(NULL != name)
+         {
+            printf("selected file (save) is \"%s\"\n", name);
+            free(name);
+         }
+         else
+         {
+            printf("file OSDIALOG_SAVE was canceled.\n");
+         }
+      }
+
+   }
+
+   // Test color dialog
+   if(argc <= 3)
+   {
+      osdialog_color color = { 80/*r*/, 120/*g*/, 160/*b*/, 200/*a*/ };
+      if(osdialog_color_picker(&color, 0/*opacity*/))
+      {
+         printf("selected color rgba=(%d, %d, %d, %d) (#%02x%02x%02x%02x)\n",
+                color.r, color.g, color.b, color.a,
+                color.a, color.r, color.g, color.b
+                );
+      }
+      else
+      {
+         printf("color picker dialog was canceled.\n");
+      }
+   }
+
+   return r;
+}
diff --git a/make.objects b/make.objects
index bf450a57..f98d8009 100644
--- a/make.objects
+++ b/make.objects
@@ -113,7 +113,9 @@ LIB_OBJ_WIN= \
 
 LIB_OBJ_LINUX= \
 	dep/lglw/lglw_linux.o \
-	dep/osdialog/osdialog_gtk2.o
+	dep/osdialog/osdialog_zenity.o
+
+# dep/osdialog/osdialog_gtk2.o
 
 SHARED_LIB_OBJ= \
 	$(COMMON_OBJ)