MicroApps are small REST applications that are designed from the ground up to be integrated with other applications. Usually, they are not directly useful on their own, but must be integrated into other applications (this is what differentiates a MicroApp from a regular REST application).
microapps.org is intended to serve as a central collection point for these apps to reduce wheel reinvention. It will also provide resources for developers of microapps and be a place to discuss this programming approach.
There is a google repository set up for hosting microapps. It's intended to be very open to anyone developing microapps or microapp related libraries/frameworks. If you'd like your microapp hosted there, or would like to contribute to one of the microapps hosted there, email your google username to AndersPearson and he'll add you. There's also now a mailing list for discussing microapps. Please join if you're interested.
Note: (the old, previous repository was at sourceforge. please switch your svn checkouts to the google repo)