Google Gadgets Editor

The easiest way to get started writing gadgets is to use the Google Gadgets Editor (GGE). GGE lets you edit gadget specs and click Preview to see the live results of your changes, without even leaving the Developer Guide. You can also use GGE to save, host, and publish gadgets.

http://code.google.com/apis/gadgets/docs/legacy/gs.html#GGE