"Sims 3 Package Interface" provides a core library of portable code that "understands" Sims3 game packages. Note that (with some minor tweaks) the core library code also understands other game package formats (e.g. SimCity Online, Sims4).
Along with the core library are a number of "wrappers" that provide the main part of the project. These handle deserialization and serialization of data within the package (or any other source).
Further tools (not supplied here) can use the core...
The Borg project is a framework for building MMORPG systems entirely written in c# . Borg provides the infrastructure and development framework with features like account authentication & management, message delivery, client and shared libraries...
Update: this project is not active. You can still use it as a solid base for other projects or research.
A virtual world engine writen by C# Provide network,serialization,thread management,work flow,cluster management,RPC etc.It's designed for concurrency. For performance, it doesn't use lock to resolve conflicts, otherwise it use queues.