Hi, Our scenario is a network scanner. It connects to a set of hosts and scans them in parallel for a while using low priority background threads. I want to be able to schedule lots of work but only have any given say ten or whatever number of hosts scanned in parallel. Even if I create my own threads, the many callbacks and other asynchronous goodness uses the ThreadPool and I end up running out of resources. I should look at MonoTorrent... If I use THE ThreadPool, can I limit my application to some number that will leave enough for the rest of the application to Run smoothly? Is there a threadpool that I can initialize to n long lived threads?