A proxy that only allows one connection through on a given port at a time.
It's happened to everyone, you want to connect on a TCP/IP socket, but you need a mutex in front of it!
Luckily, TCPLock is here for you. TCPLock is a TCP/IP proxy that only allows a single connection through at a time.
tcplock -l [port to listen to] -p [port to proxy to] -h [host to proxy to]