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).
TrinityOS is a step-by-step, example-driven HOWTO on building a very functional Linux box with strong security in mind. TrinityOS is well known for its strong packet firewall ruleset, Chrooted and Split DNS (v9 and v8), secured Sendmail (8.x), Linux PPTP, Serial consoles and Reverse TELNET, DHCPd, SSHd, UPSes, system performance tuning, the automated TrinityOS-Security implementation scripts, and much more.
'NTLM Authorization Proxy Server' (APS) is a proxy software that allows you to authenticate via an MS Proxy Server using the proprietary NTLM protocol. APS has the ability to behave as a standalone proxy server and authenticate HTTP clients at Web servers using the NTLM protocol. It can change arbitrary values in your client's request headers so that those requests will look like they were created by MS IE. It is written in Python 1.5.2.
TrustWall HTTP Proxy protects your internal Web server by acting as an inbound proxy (like a reserve Squid proxy). It can also work as a secure outbound proxy to protect your browser client. It allows you to inspect almost every detail of the HTTP protocol headers, including the URL request line, the server version, user-agent, referrer, cookie, query, etc., in a easy-to-use script-like configuration file. This program is generally considered an "Expert Tool"; you will need knowledge of the HTTP protocol to configure the proxy properly.
http_filter is an HTTP tunnel with filtering and multiplexing. It runs on a firewall, sitting in front of not-so-secure Web servers (like IIS), and it accepts requests, applies a set of rules to them, and allows the requests to be passed through to the back-end Web server only if they pass all filters. The rules can be defined globally or per-server.