Widget engines

desktop environment for Linux and FreeBSD

graphical environments provided by the KDE community

discontinued widget engine for Microsoft Gadgets

macOS dashboard system featuring programmable widgets

graphical environments provided by KDE

part of a larger software application which has a stand-alone UI and simplified features

XULRunner is a discontinued, packaged version of the Mozilla platform to enable standalone desktop application development using XUL, developed by Mozilla. It replaced the Gecko Runtime Environment, a stalled project with a similar purpose. The first stable developer preview of XULRunner was released in February 2006, based on the Mozilla 1.8 code base. Mozilla stopped supporting the development of XULrunner in July 2015.

Rainmeter is a free and open-source desktop customization utility for Windows released under the GNU GPL v2 license. It allows users to create and display user-generated customizable desktop widgets or applets called "skins" that display information. Ready to use collections of skins can be downloaded and installed in packages known as "suites".

file format

applet intended to be used within web pages

Discontinued application platform

lightweight single-purpose applications