Yahoo! Widgets was a free application platform for Mac OS X and Microsoft Windows. The software was previously called Konfabulator, but after being acquired by computer services company Yahoo! in 2005 it was rebranded. The name Konfabulator was subsequently reinstated as the name of the underlying rendering engine. The engine uses a JavaScript runtime environment combined with an XML interpreter to run small applications referred to as widgets, and hence is part of a class of software applications called widget engines.

According to the site referred to in the box to the right, "Yahoo! Desktop Widgets Gallery Website Discontinued on April 11, 2012". Yahoo has made it clear that although support for the Desktop Widget Gallery Website has been withdrawn it does not mean that the yahoo widget engine will suddenly stop working, in fact it should be fully functional for the foreseeable future.

Yahoo! Widget Engine includes some default widgets to get users started, including a weather widget, a digital clock, and a calendar among other things. Some of the most downloaded ones include a world timezone clock, dedicated countdown timers, simple RSS feed readers, and webcam viewers.