DeleGate is a general purpose application level gateway, or a proxy
server which runs on multiple platforms (Unix, Windows and OS/2).
DeleGate mediates communication of various protocols (HTTP, FTP, NNTP,
POP, Telnet, etc.), applying cache and conversion for mediated data,
controlling access from clients and routing toward servers.  It
translates protocols between clients and servers, merging several
servers into a single server view with aliasing and filtering.  Born
as a tiny proxy for Gopher in March 1994, it has steadily grown into a
general purpose proxy server.  Besides proxy, DeleGate can be used as a
simple origin server for some protocols (HTTP, FTP and NNTP).

Homepage:
http://www.delegate.org/delegate/
