We released DarkNet recently -
DarkNet is a multiplayer plugin specifically designed for use in game development. It uses both UDP and TCP protocol making it suitable for virtually any type of online game ranging from fast paced first person shooters to large scale massively multiplayer online games. It is very easy to use and well documented with several code examples. DarkNet is compatible with Dark Basic Professional, C++ and .NET compatible languages (e.g. C#, VB.NET).
More information can be found here -