ptf is a simple TCP forwarder written in Python. It is not (yet) usable for FTP but many other protocols such as IRC (without DCC) or NNTP.
You can download it from the following link: https://packetstormsecurity.com/files/download/11692/ptf-0.4.tar.gz
Source: https://packetstormsecurity.com/files/11692/ptf-0.4.tar.gz.html