Squid Proxy Cache Server

Squid is a free and open-source caching and forwarding HTTP web proxy that provides proxy services and caching for web content, reducing bandwidth usage and improving response times. Originally developed in 1990 as Harvest Cache by Peter Danzig and Anawat Chankhunthod at the University of Colorado Boulder, Squid evolved from the Harvest project and has been maintained by the community since 1996, with active contributions from thousands of developers. Key features: HTTP caching: caches frequently accessed web objects (HTML pages, images, JavaScript, CSS, videos) to reduce bandwidth consumption and improve response times. Both memory cache (RAM) and disk cache (aufs, diskd, or rock storage formats) are supported. Forward proxy: acts as an intermediary for internal network users accessing the internet, providing centralized caching, access control, and monitoring. Reverse proxy: caches content from origin web servers, acting as a load balancer and reducing backend load. Authentication: supports Basic, Digest, NTLM, Negotiate (Kerberos), with external helpers for LDAP, RADIUS, PAM, and SMB. Access Control Lists: fine-grained access control based on source IP, destination domain, URL path, time of day, protocol, MIME type, and HTTP method. SSL/TLS interception: optional SSL Bump for inspecting HTTPS traffic via dynamic certificate generation. ICAP and eCAP: integration with external content adaptation services (antivirus, content filtering). WCCP: Web Cache Coordination Protocol for Cisco router integration. Monitoring: extensive logging (access log, cache log) and SNMP. ICP, HTCP: inter-cache coordination for cache hierarchies. Cross-platform: Linux, macOS, Windows, BSD. GPLv2.