Squid cache, or simply Squid, is a type of proxy server. They have many different uses, including making web servers faster. It is mostly used in HTTP and FTP protocols, but it has some support for some other types of protocols, like SSL, TLS, and HTTPS. It has been made over several years by people in the University of California in San Diego. It was made to be run on Linux-type computers, but with the use of Cygwin, it can also run completely on Windows computers. It is licensed under the GNU General Public License.