This is a comparison of widget engines. This article is not about widget toolkits that are used in computer programming to build graphical user interfaces.
General
Engine Creator Current Version License Status Adobe AIR Adobe Systems 1.5 Proprietary Discontinued AveDesk Andreas Verhoeven 1.3 Proprietary Abandoned Dashboard Apple Inc. Proprietary Retired DesktopX Stardock 3.5 Proprietary Abandoned gDesklets Martin Grimme and Christian Meyer 0.36 GPL Abandoned Google Desktop Gadgets Google 5.0.0701.18382 Proprietary Discontinued Kapsules Andrew Powell 0.9.9 Proprietary Abandoned KlipFolio Serence 5.0D Proprietary Active and supported Microsoft Gadgets Microsoft Proprietary Discontinued NetFront Access Co. Ltd. 4.2 Proprietary Discontinued Netvibes Netvibes 1.0 Proprietary Active and supported Plasma KDE (Aaron Seigo, main developer) GPL Active and Supported Rainmeter Kimmo 'Rainy' Pekkola GPL Active and Supported Screenlets Rico Pfaus (AKA RYX) 0.1.5 GPL Abandoned Serious Samurize Gustaf & Oscar Lundh 1.64 Proprietary Abandoned SuperKaramba Hans Karlsson 0.39 GPL Abandoned WebKit Apple Inc. ? BSD+LGPL Active and supported WidSets Nokia Proprietary Discontinued Yahoo! Widgets Ed Voas, Michael Galloway, and Sam Magnuson 4.5.2 Proprietary Discontinued Engine Creator Current Version License Status
Operating system support Engine Mac OS X Windows NT5 (XP) Windows NT6 (Vista, 7/8/10+) Linux Android Adobe AIR AveDesk Dashboard DesktopX gDesklets Google Desktop Gadgets Kapsules KlipFolio Microsoft Gadgets NetFront Netvibes Dashboard bridge Plasma Rainmeter Screenlets Serious Samurize SuperKaramba WebKit WidSets Yahoo! Widgets Engine Mac OS X Windows XP (NT5) Windows (NT6) Vista+ Linux Android
Technical
Languages Which programming languages the engines support. Most engines rely upon interpreted languages. Engine HTML XHTML CSS XML JavaScript Perl Python Ruby C++ Executable VBScript Adobe AIR AveDesk Dashboard DesktopX gDesklets Google Desktop Gadgets Kapsules KlipFolio Microsoft Gadgets (as ActiveX) Netvibes Plasma Rainmeter Screenlets Serious Samurize SuperKaramba WebKit WidSets Yahoo! Widgets Engine HTML XHTML CSS XML JavaScript Perl Python Ruby C++ Executable VBScript
Formats and Development Engine IDE Widget Container Widget MIME Type Adobe AIR ZIP application/vnd.adobe.air-application-installer-package+zip AveDesk ZIP Dashboard ZIP application/x-macbinary DesktopX EXE gDesklets Tar.gz Google Desktop Gadgets ZIP app/gg Kapsules ZIP KlipFolio Proprietary XML Format Microsoft Gadgets ZIP application/x-windows-gadget Netvibes Online Plasma ZIP, with plasmoid as extension instead of zip Rainmeter ZIP, with rmskin as extension instead of zip application/vnd.rainmeter.SkinInstaller Screenlets Tar.gz Serious Samurize ZIP SuperKaramba Tar.gz WebKit WidSets Yahoo! Widgets Proprietary Format, ZIP application/vnd.yahoo.Widget Engine IDE Widget Container Widget MIME Type
Development Tools As widgets are largely combinations of HTML or XHTML, CSS, and Javascript in most cases, standard AJAX tools, such as Eclipse ATF, can be used for development. Specialized tools may give access to additional capabilities supplied by frameworks such as Dojo or Openrico.
References