SafeSquid : A content filtering proxy server

SafeSquid is a content filtering proxy server. It supports 'profiled' Internet access, a browser based interface, very fast throughput, DNS caching, content caching, pre-fetching, bandwidth control, virus scanning, ICP, CARP, and ICAP clients, source, target, and time-based granular firewall style rules to allow or deny content like music, videos, Flash and Java applets, messengers, chats, cookies, ActiveX, scripts, etc., remote authentication, real-time text and image analysis for blocking pornography, and an URL filter.

• Operating Systems : POSIX Linux

ModSecurity : An intrusion detection and prevention engine for Web applications (sometimes called a Web application firewall)

ModSecurity is an intrusion detection and prevention engine for Web applications (sometimes called a Web application firewall). Operating embedded or as part of an Apache reverse proxy, it increases Web application security, protecting Web applications from known and unknown attacks. It is flexible and easy to configure. It monitors HTTP traffic (including POST payloads), detects or prevents attacks, enhances logging, performs anti-evasion, and allows administrators to create custom rules to suit their specific needs. It excels in HTTP traffic monitoring and just-in-time vulnerability patching.

• Licenses : GPLv2
• Operating Systems : OS Independent
• Implementation : C

DeleGate : A multi-purpose application level gateway or proxy server

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).

• Licenses : Free for non-commercial use
• Operating Systems : Unix, Mac OS X, Windows, Mobile
• Implementation : C

The CyaSSL software package : A fast, dual-licensed implementation of SSL for embedded and small footprint devices

The CyaSSL software package is a fast, dual-licensed implementation of SSL for embedded and small footprint devices. It includes SSL client libraries and an SSL server implementation. It supports multiple APIs including an OpenSSL compatibility interface. TLS 1.1 is supported along with cipher suites for AES, 3DES, RC4, HC-128, and RABBIT.

• Licenses : GPL
• Operating Systems : Mac OS X, Windows, POSIX, Linux, Unix
• Implementation : C