Index: ps/trunk/source/main.cpp
===================================================================
--- ps/trunk/source/main.cpp
+++ ps/trunk/source/main.cpp
@@ -177,6 +177,23 @@
 		QuitEngine();
 		break;
 
+	case SDL_DROPFILE:
+	{
+		char* dropped_filedir = ev->ev.drop.file;
+		const Paths paths(g_args);
+		CModInstaller installer(paths.UserData() / "mods", paths.Cache());
+		installer.Install(std::string(dropped_filedir), g_ScriptContext, true);
+		SDL_free(dropped_filedir);
+		if (installer.GetInstalledMods().empty())
+			LOGERROR("Failed to install mod %s", dropped_filedir);
+		else
+		{
+			LOGMESSAGE("Installed mod %s", installer.GetInstalledMods().front());
+			RestartEngine();
+		}
+		break;
+	}
+
 	case SDL_HOTKEYPRESS:
 		std::string hotkey = static_cast<const char*>(ev->ev.user.data1);
 		if (hotkey == "exit")
Index: ps/trunk/source/tools/dist/build-osx-bundle.py
===================================================================
--- ps/trunk/source/tools/dist/build-osx-bundle.py
+++ ps/trunk/source/tools/dist/build-osx-bundle.py
@@ -107,6 +107,27 @@
         'LSHasLocalizedDisplayName': True,
         'LSMinimumSystemVersion': BUNDLE_MIN_OSX_VERSION,
         'NSHumanReadableCopyright': f'Copyright © {datetime.datetime.now().year} Wildfire Games',
+        'UTExportedTypeDeclarations': [{
+            'UTTypeIdentifier': BUNDLE_IDENTIFIER,
+            'UTTypeTagSpecification': {
+                'public.filename-extension': ["pyromod"],
+            },
+            'UTTypeConformsTo': ['public.zip-archive'],
+            'UTTypeDescription': '0 A.D. Zipped Mod',
+            'UTTypeIconFile': '0ad'
+        }],
+        'CFBundleDocumentTypes': [{
+            'CFBundleTypeExtensions': ['pyromod'],
+            'CFBundleTypeRole': 'Editor',
+            'CFBundleTypeIconFile': '0ad',
+            'LSHandlerRank': 'Owner'
+        },
+        {
+            'CFBundleTypeExtensions': ['zip'],
+            'CFBundleTypeRole': 'Viewer',
+            'CFBundleTypeIconFile': '0ad',
+            'LSHandlerRank': 'Alternate'
+        }],
     }, f)
 
 if args.dev: