Comparison of widget engines

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

Widget engines that are discontinued are marked in a different color.

Engine	Creator	Current Version	License
adesklets	Sylvain Fourmanoit	0.6.1	GPL
Adobe AIR	Adobe Systems	1.5	Adobe AIR EULA
AveDesk	Andreas Verhoeven	1.3	Donationware
Dashboard	Apple Computer	Template:Latest stable release/Dashboard	Part of Mac OS X since version 10.4
DesktopX	Stardock	3.5	Shareware
gDesklets	Martin Grimme and Christian Meyer	0.36	GPL
Google Desktop Gadgets	Google	5.0.0701.18382	Freeware
Template:Rh2 | Kapsules	Andrew Powell	0.9.9	Freeware
KlipFolio	Serence	5.0D	Freeware
Microsoft Gadgets	Microsoft	?	Part of Windows Vista
NetFront	Access Co. Ltd.	3.5
Netvibes	Netvibes	1.0	Free API
Opera	Opera Software	Template:Latest stable software release/Opera	Freeware
Plasma	KDE (Aaron Seigo, main developer)	4.3	GPL
Screenlets	Rico Pfaus (AKA RYX)	0.1.2	GPL
Serious Samurize	Gustaf & Oscar Lundh	1.64	Semi-free software
SuperKaramba	Hans Karlsson	0.39	GPL
WebKit	Apple Computer	?	Freeware
WidSets	Nokia	?	Freeware
Yahoo! Widgets	Ed Voas, Michael Galloway, and Sam Magnuson Template:Refun	4.5.1	Freeware
Engine	Creator	Current Version	License

• ^  The Yahoo! Widgets was originally released by Arlo Rose and Ed Voas as Konfabulator. The name was changed several months after Yahoo! acquired the software in July 2005.

Operating system support

Engine	Mac OS X	Windows XP	Windows Vista	Linux
adesklets	No	No	No	Yes
Adobe AIR	Yes	Yes	Yes	Yes
AveDesk	No	Yes	Yes	No
Dashboard	Yes	No	No	NoTemplate:Refun
DesktopX	No	Yes	Yes	No
gDesklets	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun	Yes
Google Desktop Gadgets	Yes	Yes	Yes	Yes
Template:Rh2 | Kapsules	No	Yes	?	No
KlipFolio	No	Yes	Yes	No
Microsoft Gadgets	No	No	Yes	No
NetFront	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun
Netvibes	Dashboard bridge	Using browser	Using browser	Using browser
Opera	Yes	Yes	Yes	Yes
Plasma	Yes	Yes	Yes	Yes
Screenlets	No	No	No	Yes
Serious Samurize	No	Yes	YesTemplate:Refun	No
SuperKaramba	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun	Yes
WebKit	?	?	?	?
WidSets	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun	NoTemplate:Refun
Yahoo! Widgets	Yes	Yes	Yes	No
Engine	Mac OS X	Windows XP	Windows Vista	Linux

• ^  As for the next major version the gDesklets' developers are planning to support Windows XP and Mac OS X.
• ^  Early versions of Windows Sidebar have been successfully ported to Windows XP, though this activity is forbidden under the EULA.
• ^  The current version of Samurize (1.64.2) runs on Vista but there are a few minor issues that need to be worked out, such as security dialog prompts.
• ^  Google Desktop for Linux requires an additional download (Google Gadgets for Linux) to run Google Desktop Gadgets.
• ^  WidSets is for mobiles and runs on the Java MIDP 2.0 platform
• ^ NetFront is a Mobile browser, which is also preinstalled on the PSP, and on the PlayStation 3.

Technical

Languages

What programming languages the engines support. Most engines rely upon interpreted languages.

Engine	HTML	XHTML	CSS	XML	JavaScript	Perl	Python	Ruby	C++	Executable
adesklets	No	No	No	No	No	Yes	Yes	No	No	No
Adobe AIRTemplate:Refun	Yes	Yes	Yes	Yes	Yes	?	?	?	?	?
AveDeskTemplate:Refun	No	No	Yes	Yes	Yes	No	No	No	Yes	?
Dashboard	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	YesTemplate:Refun	YesTemplate:Refun
DesktopX	Yes	Yes	Yes	Yes	Yes	Yes	Yes	?	Yes	Yes
gDeskletsTemplate:RefunTemplate:RefunTemplate:Refun	No	No	No	Yes	No	No	Yes	No	No	No
Google Desktop Gadgets	?	?	?	Yes	Yes	No	No	No	No	Yes
Template:Rh2 | KapsulesTemplate:Refun	?	?	?	?	No	Yes	Yes	No	?	?
KlipFolio	No	No	YesTemplate:Refun	Yes	Yes	No	No	No	No	No
Microsoft Gadgets	Yes	No	Yes	Yes	Yes	No	Yes	Yes	Yes (as ActiveX)	Yes
NetFrontTemplate:Refun	Yes	Yes	Yes	Yes	Yes	No	No	No	No	No
Netvibes	Yes	Yes	Yes	Yes	Yes	No	No	No	No	No
OperaTemplate:Refun	Yes	Yes	Yes	Yes	Yes	No	No	No	No	No
Plasma	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	Yes	?
Screenlets	?	?	?	?	No	No	Yes	No	?	?
Serious SamurizeTemplate:RefunTemplate:Refun	No	No	No	No	Yes	Yes	Yes	Yes	Yes	Yes
SuperKaramba	?	?	Yes	Yes	Yes	No	Yes	Yes	Yes	?
WebKit	Yes	Yes	Yes	Yes	Yes	No	No	No	Yes	?
WidSets	?	?	?	?	?	?	?	?	?	?
Yahoo! WidgetsTemplate:Refun	Yes	Yes	Yes	Yes	Yes	No	No	No	No	NoTemplate:Refun
Engine	HTML	XHTML	CSS	XML	JavaScript	Perl	Python	Ruby	C++	Executable

• ^  AveDesk can be extended using AveScripter, which supports plugins written with XML and Javascript, extended using CSS.
• ^  Widgets for Kapsules and Serious Samurize can be written in any scripting language for which there is an ActiveScript engine, including PHP, JScript, VBScript and Ruby.
• ^  This is only relevant for Opera's and NetFront's extensions; the web browsers themself support HTML, CSS and others.
• ^  Samurize supports DLLs compiled with C++, Delphi, PowerBASIC, and FreeBasic, among others. HTML/XML/CSS support can be added by using certain plugins.
• ^  Yahoo! Widget Engine supports Perl and Python indirectly through the use of the shell, provided that the interpreters are installed on the machine (on Mac OS X, they are by default).
• ^  gDesklets might support Perl scripting through PyPerl [1] in the next major version.
• ^  The next major version of gDesklets will support Yahoo! Widgets. Thus, JavaScript support will be included, too.
• ^  gDesklets will provide some CSS like dialect in the next major version.
• ^  KlipFolio supports custom styles using CSS syntax.
• ^  Yahoo! Widgets can interface with COM (windows) or AppleScript (Mac OS)
• ^  Dashboard uses a technology called Cocoa Plugins.This allows for Objective-C code to be used through the plugin. The plugin is written with Cocoa and is compiled.
• ^ Widgets for Adobe Air can also be programmed in Adobe Flash, and Actionscript.

Formats and Development

Engine	IDE	Widget Container	Widget MIME Type
adesklets	?	?	?
Adobe AIR	Flex Builder 3, Flash CS4, Dreamweaver CS4	ZIP	application/vnd.adobe.air-application-installer-package+zip
AveDesk	AveScripter	ZIP	?
Dashboard	Dashcode	ZIP	application/x-macbinary
DesktopX	Desktop X Pro	EXE	?
gDesklets	No	Tar.gz	?
Google Desktop Gadgets	Google Desktop Gadget Designer	ZIP	app/gg
Template:Rh2 | Kapsules	?	ZIP	?
KlipFolio	No	Proprietary XML Format	?
Microsoft Gadgets	NoTemplate:Refun	ZIP	application/x-windows-gadget
NetFront	No	ZIP	application/x-opera-widgets
Netvibes	No	Online	?
Opera	Opera Dragonfly	ZIP	application/x-opera-widgets
Plasma	No	ZIP, with plasmoid as extension instead of zip	?
Screenlets	No	Tar.gz	?
Serious Samurize	Serious Samurize Config Editor	ZIP	?
SuperKaramba	No	Tar.gz	?
WebKit	No	?	?
WidSets	?	?	?
Yahoo! Widgets	NoTemplate:Refun	Proprietary Format, ZIP	application/vnd.yahoo.Widget
Engine	IDE	Widget Container	Widget MIME Type

• ^ Microsoft Gadget have documentation, but no IDE to aid development.
• ^ Yahoo! Widgets have documentation, but no IDE to aid development.

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.