1. Ugui MvvmUnity3D uGUI mvvm databinding via the standard IXChanged interfaces used in wpf (INotifyPropertyChanged, INotifyCollectionChanged, etc)
3. PnetNetworking middleware for unity using Lidgren, with a custom dedicated server. This library is now obsolete in favor of its successor: https://bitbucket.org/jbruening/pnet2
4. UnEnginea clone of the UnityEngine.dll - so you can write and test scripts outside of unity