I want my FTP: bits on demand

A look under the hood of the IETF's file transfer protocol, including a summary of the commands in the FTP standard. Today, FTP is used primarily for maintaining archives of public files, and is losing ground to HTTP even there. FTP simply doesn't maintain as much metadata: not creation date, not original location, not application data type. Its addressing structure is an opaque pathname at a host. Consider that in the context of mirroring or relocating information: FTP mirrors are an ad hoc, user driven abstraction; HTTP can send automatable redirection messages. Per-site metadata is also provided manually as OOindex files, compared to automatable Web spiders.