Bjoern

AlphaFS - Bringing Advanced Windows Filesystem Support to .NET
ASP.NET MVC / Web API / Web Pages
Behavior Trees XNA Game Component
BEPUphysics
Caliburn Micro: WPF, Silverlight, WP7 and WinRT/Metro made easy.
dIRca WP7 IRC Client
DirectCanvas
DirectX for WPF
Floe IRC Client
FujiyBlog
Jounce: Silverlight MVVM + MEF Framework
Json.NET
Jurassic - A Javascript Compiler for .NET
NAudio
Nuclex Framework
OData SDK for PHP
ReactiveProperty - MVVM Extensions for Rx
Silverlight Toolkit
SilverSynth - Digital Audio Synthesis for Silverlight
Snoop, the WPF Spy Utility