Are there any good open-sourced comet web servers for ASP.NET MVC applications?

I'm looking for one that can be used to handle many long poll clients and does not create a thread for开发者_如何学运维 each request.

Each call to IIS (ASP.NET) page works on its own thread. A good library should not create some extra threads. So, I'm using PokeIn inside my solution(online learning) and it doesnt create extra threads. It has a free community edition but not an open source :(

you can check the source code for Pokein here

edit
It seems that the latest source available isn't that up to date, my bad. Check out their website instead.
I've been using it