jlyonsmith 

An extremely useful collection of utility classes for .NET

A simple, low overhead unit test library for Mono. It's is based on the API's from NUnit and MSTest.

PCL ToolBelt for Applications

Plugins and utility classes for REST API projects using Mono, ServiceStack, MongoDB and RQL

TSON: Typeable Simple Object Notation. Fully compatible with JSON, but with relaxed syntax rules that make it much easier for humans to type, plus it supports commenting using #.

REST Query Language (RQL). A simple, extensible query languaged for REST API's.

RQL binding for MongoDB.

Game content creation and compilation tools

A collection of tools for working with C# and other code