Code.gov - Share & reuse open source code from the Federal Government
CodeShare.io - Realtime code sharing for developers
Anonypoll - Anonymous polls platform to seek and share honest opinions
LocalWiki - Collect, share & open the world's local knowledge
Visual Studio Live Share - Real-time collaborative development
Urbanpinion - Citizens engagement platform that lets you create a landing page with an interactive map in just a few steps, launch a survey and collect citizens' ideas and votes - and make the right decisions for the city development.