Nearforums is a lightweight powerful discussion forum that can be installed within minutes on Linux or Windows servers with MySQL or MS SQL database servers. It includes great features like sign-in with Facebook/Twitter, navigation with tags, full Web administration, built-in search engine, RSS feeds, and accessible HTML. It is SEO friendly.
The Dextop application framework allows you to create Rich Internet Applications based on .NET/Mono and Sencha Ext JS. It has proven to be useful for online business applications. It features a desktop-like Ext JS frontend, simplified client-server communication, a stateful programming model, real-time updates and notifications from the server, automatic column model generation, automatic store model generation, and automatic form generation.
Git# is a C# implementation of the Git version control system for the .NET platform. It is meant to be fully compatible to the original Git implementation in C for Linux. It can be used as a stand-alone command line application (potentially replacing msysGit on Windows) or as a library for applications such as GUI frontends or plugins for IDEs.