Libraries (or code) for processing TCP/IP commands?

Projects Networking, Protocols, and Devices
1

I'd like to have my Arduino listen for commands via TCP/IP and then process them when a full command is received.

For example, if I telnet into my Arduino and send the string "BEEP" (followed by a carriage return/linefeed) I'd like it to call a function and process it.

There are several examples of this online but none of them seem to work correctly (especially during heavy-load situations).

Are there any libraries (or code) for a rock-solid, extremely stable, TCP/IP command processing?

2

I have telnet-like code on the playground. It doesn't have a timeout, but it is fairly well tested.
http://playground.arduino.cc/Code/Telnet