BITNET was a co-operative U.S. university computer network founded in 1981 by Ira Fuchs at the City University of New York (CUNY) and Greydon Freeman, Inc. at Yale University. The first network link was between CUNY and Yale.
The name BITNET originally meant "Because It's There Network", but it eventually came to mean "Because It's Time Network".
A college or university wishing to join BITNET was required to lease a data circuit (phone line) from a site to an existing BITNET node, buy modems for each end of the data circuit, sending one to the connecting point site, and allow other institutions to connect to its site free of charge.
Bitnet's NJE (Network Job Entry) , called RSCS, were used for the huge IBM internal network known as VNET. BITNET links originally ran at 9600 baud. The BITNET were eventually ported to non-IBM mainframe operating systems, and became particularly widely implemented under VAX/VMS, in addition to DECnet.
BITNET featured email and LISTSERV software, but predated the World Wide Web, the common use of , and . Gateways for the lists made them available on Usenet. BITNET also supported interactive transmission of files and messages to other users. A gateway service called TRICKLE enabled users to request files from Internet FTP servers in 64 Kb UUencoded chunks. The Interchat Relay Network, popularly known as Bitnet Relay, was the network's instant messaging feature.