You can factor out most of your code into a separate thread:
static void Main(string[] args)
{
TcpListener listener = new TcpListener(IPAddress.Any , 8000);
TcpClient client;
listener.Start();
while (true) // Add your exit flag here
{
client = listener.AcceptTcpClient();
ThreadPool.QueueUserWorkItem(ThreadProc, client);
}
}
private static void ThreadProc(object obj)
{
var client = (TcpClient)obj;
// Do your work here
}