P4.Net is an API for the Microsoft .Net Common Language Runtime (CLR). It can be used from any managed language including C#, VB.Net, and J#.
P4.Net is protected under this license, which is the MIT license.
P4.Net is supported by me personally, in my spare time. If you have any issues you can contact me at p4shawn <at> gmail <dot> com. I use P4.Net at work extensively, so I'm motivated to fix any bugs. But I can't guarantee I'll be able to help everyone in a timely fashion, or even at all.