A caching HTTP/HTTPS proxy. Pages that pass through the proxy are indexed and can be searched using a built-in HTTP server. [Open Source, GPL]

Acts as a local proxy between the browser and the insecure Internet. All web pages requested by the browser go directly to JAP, and are multiply encrypted there. The encrypted messages travel through a chain of servers (named Mixes by the inventor of ...

Speeds up surfing over slow links by removing unnecessary parts (like background images) while still showing the page mostly like it is. Removes advertisements, compresses text, and images. [Open Source, BSD-like]

A deliberately slow proxy to simulate the dial-up modem experience. [Open Source, GPL]

Proxying, filtering cache server. Speeds up surfing and can block ad banners. Also has privacy features such as selective cookie filtering, changing HTTP referrer and browser name. [Open Source, GPL] Development has been suspended due to security issues.

Java internet proxy server and surveillance monitor written in 100% pure JAVA language. Handles HTTP, HTTPS, SMTP/POP3, FTP, SOCKSv5, TELNET. Also can detected and filtered out annoying Javascript PopUp windows, advertisements and promotions.

SecurityFocus reports the Java Anonymous Proxy (JAP), used to anonymise access to the Internet, has been back-doored by court order.

Provides HTTP tunneling for EJB, RMI, JNDI, JMS, and CORBA APIs for communication between client and J2EE and CORBA services. [Commercial]

Supports SOCKS4 and SOCKS5 protocols, and Identd authentication. [Open Source, GPL]

Lets users access computers behind a firewall. Includes SOCKS and Web proxy as a user program interface. [Freeware]