Circuit level proxy with firewall, supports SOCKS, msproxy and http proxy. Port redirection and bandwidth usage control available through add on modules. [Unix]

Offers web caching, firewall, mail server, access control and activity logging. [Windows]

ComTun Pro, offers connection sharing, firewall, spam filtering and caching. [Windows]

Offers application layer FTP service proxying to facilitate use of service through firewalls. Supports various access control options. [Unix, Linux, BSD, Windows]

InterGate software offers web caching, stateful inspection firewall, content filtering and network management services. Anti spam module also available. [Mac OS, Windows]

Configurable IRC proxy. Downloads and product news.

HTTP/HTTPS proxy that runs from inetd, and uses less than 1kb of diskspace. [Unix]

A light-weight customizable HTTP proxy daemon. Free software licensed under the GNU GPL. [POSIX]

Offers mail and news server hosting, web caching and activity logging. Trial downloads, online ordering and PDF documentation. [Windows]

HTTP proxy that enhances user privacy by deleting (or faking) eight data elements, including the Cookie field and Referrer fields, from web browser responses. [Windows]