File Service Protocol
File Service Protocol (FSP) is a UDP-based replacement for the File Transfer Protocol, designed for anonymous access with lower hardware and network requirements than FTP. In particular, because it uses UDP, it avoids the problems that many FTP servers have had with requiring a separate process for each client, and because it is built to use an unreliable protocol, it can more easily handle resuming a transfer after a network failure. == History == FSP never reached the popularity of FTP for legitimate use (although wuarchive and id Software provided FSP service in addition to FTP for some time), but became very popular in the early-to-mid-1990s for underground sites containing pornography and/or warez.