DeleGate is a multi-purpose application level gateway or proxy server that mediates communication of various protocols, applying cache and conversion for mediated data, controlling access from clients, and routing toward servers. It translates protocols between clients and servers, converting between IPv4 and IPv6, applying SSL (TLS) to arbitrary protocols, merging several servers into a single server view with aliasing and filtering. It can be used as a simple origin server for some protocols (HTTP, FTP, and NNTP).
httpMonitor is a Python program which lets you monitor the HTTP traffic between a browser and a Web server. You configure your browser to use httpMonitor as its proxy to ensure that all HTTP traffic between browser and server goes via httpMonitor. In a XML-configuration file you can specify a Python-function as processor for the HTTP-messages you are interested in (requests or responses, which match certain criteria). You may have as many processors as you want, without modifying the actual program. The only thing you need to do is configure the httpMonitor and write your processors.
jftpgw is a proxy server for the FTP protocol. It is highly configurable, allowing you to use an XML-like configuration file to define almost any combination of the client's IP, the server's IP, the user name, the destination port, and so on. jftpgw supports inetd/daemon mode, transparent proxying, forwards, caching, logging, data IP and port specification (port ranges), limiting of the number of simultaeous sessions, and several proxy login styles for clients that support FTP proxies.
squid_redirect uses a list of patterns to zap annoying ad banners from Web pages, inserting a placeholder image. It lives in a Web proxy and so requires no special browser facilities. It's readily customizable, small, fast, and easy to install. (In Debian/Ubuntu, this program is named "adzapper".)
The stunnel program is designed to work as an SSL encryption wrapper between remote client and local (inetd-startable) or remote server. It can be used to add SSL functionality to commonly used inetd daemons like POP2, POP3, and IMAP servers without any changes in the programs' code. It will negotiate an SSL connection using the OpenSSL or SSLeay libraries. It calls the underlying crypto libraries, so stunnel supports whatever cryptographic algorithms you compiled into your crypto package.
The WWWOFFLE programs simplify World Wide Web browsing from computers that use intermittent (dialup) connections to the Internet. It is a simple proxy server with special features for use with dial-up Internet links. It makes it possible to browse Web pages and read them without having to remain connected. There are too many features to mention, but they include privacy control, cookie/advert blocking, efficient bandwidth usage by specifying intervals between refreshes, options to monitor pages regularly, recursive fetching, HTML cleaning, highlighting of cached links, indexes of cached pages, searching of cached pages, and many more.
FreeRADIUS is a high-performance, highly configurable, and feature-rich RADIUS server. Supported features include EAP (wireless authentication, PEAP, TTLS), MySQL, PostgreSQL, Oracle, LDAP, X9.9 token cards, VMPS, and many more. It comes with more than 50 vendor dictionaries, and interoperates with many others. It is the only open source RADIUS server that has implemented EAP, and it is currently deployed in multiple million-user systems.
PostArmor (formerly MailArmor) helps to keep your electronic mailbox free of spam: it looks at the relevant parts of your email before it leaves the mail server, and lets the legitimate messages pass through undisturbed, while leaving suspect messages on the server to be reexamined later or just deleted after a while. It works as a POP3 email proxy, with support for POP, APOP, and IMAP servers. It supports SpamCop reports and blacklist, and the ORDB and OSIRUSOFT blacklists.
Privoxy is a Web proxy based on Internet Junkbuster with advanced filtering capabilities for protecting privacy, filtering Web page content, managing cookies, controlling access, and removing ads, banners, pop-ups, and other obnoxious Internet junk. Privoxy has a very flexible configuration and can be customized to suit individual needs and tastes. Privoxy is useful for both stand-alone systems and multi-user networks.