Squid (software)

Squid is a caching and forwarding HTTP web proxy. It has a wide variety of uses, including speeding up a web server by caching repeated requests, caching World Wide Web (WWW), Domain Name System (DNS), and other computer network lookups for a group of people sharing network resources, and aiding security by filtering traffic. Although used for mainly HTTP and (FTP), Squid includes limited support for several other protocols including Internet Gopher, Secure Sockets Layer (SSL), Transport Layer Security (TLS), and Hypertext Transfer Protocol Secure (HTTPS). Squid does not support the SOCKS protocol, unlike Privoxy, with which Squid can be used in order to provide SOCKS support. Squid was originally designed to run as a daemon on Unix-like systems. A Windows port was maintained up to version 2.7. New versions available on Windows use the Cygwin environment. Squid is free software released under the GNU General Public License. Squid was originally developed as the Harvest object cache, part of the Harvest project at the University of Colorado Boulder. Further work on the program was completed at the University of California, San Diego and funded via two grants from the National Science Foundation. Duane Wessels forked the "last pre-commercial version of Harvest" and renamed it to Squid to avoid confusion with the commercial fork called Cached 2.0, which became NetCache. Squid version 1.0.0 was released in July 1996. SquidNT, a port of the Squid proxy server was merged into the main Squid project in September 2006. Squid is now developed almost exclusively through volunteer efforts. After a Squid proxy server is installed, web browsers can be configured to use it as a proxy HTTP server, allowing Squid to retain copies of the documents returned, which, on repeated requests for the same documents, can reduce access time as well as bandwidth consumption. This is often useful for Internet service providers to increase speed to their customers, and LANs that share an Internet connection.