A widget is a small pretty looking self contained program that runs on the desktop and performs a specific function.Widgets require a platform to run and there are several available for both Windows and Linux. 1. Screenlets: Probably the best looking widget platform available for Linux. The widgets are cute and very similar to those offered by Yahoo and Apple. 2. SuperKaramba: One of the most popular widget engines for the KDE desktop. The widgets are referred to as themes. There are plenty to download at kdelook.org 3. gDesklets: Another very nice looking widget engine. gDesklets is not restricted to one desktop environment, but currently works on most of the modern Unix desktops (including GNOME, KDE, Xfce). The support for a wide variety of desktop enviroment is a very helpful feature of gDesklets. 4. aDesklets: adesklets is an interactive Imlib2 console for the X Window System. It provides to scripted languages a clean and simple way to write great looking, mildly interactive desktop integrated graphic applets. The collection isn't that great and won't find variety, but desklets for popular tasks are available. 5. Moonlight Desklets: Moonlight is Novell's nascent open-source implementation of Microsoft's Silverlight framework for rapid, rich media application development. This is a relatively new engine so not many widgets are available. But they have some really nice looking widgets nonetheless. 6. Opera widgets: Opera widgets run on top of the Opera browser (version 9 and above), the only browser that supports widgets. There are more than a thousand Opera widgets available. I already wrote about some useful Opera widgets before. 7. Jackfield: Jackfield isn't actually a widget engine. It's an application for the Gnome desktop that can run widgets of other popular platforms like Yahoo, Apple, Microsoft Vista Sidebar and Opera. If you use this application you get access to thousands of widgets from all the 4 platforms!!