Squid is a high-performance proxy caching server for web clients, supporting FTP and HTTP data objects. Squid keeps metadata and especially hot objects cached in RAM, caches DNS lookups, supports non-blocking DNS lookups, and implements negative caching of failed requests. Squid 6.x is the latest release series, and needs a C++17 compiler to build.

WWW: http://www.squid-cache.org/
