DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
BalanceNG is a modern, IPv6 capable software IP load balancing solution. It is small, fast, and easy to use and set up. It offers session persistence, different distribution methods (Round Robin, Random, Weighted Random, Least Session, Least Bandwidth, Hash, Agent, and Randomized Agent) and a customizable UDP health check agent in source code. It supports VRRP to set up high availability configurations on multiple nodes. It supports SNMP, integrating the BALANCENG-MIB with Net-SNMPD. It implements a very fast in-memory IP-to-location database, allowing powerful location-based server load-balancing.
HAproxy is a high-performance and highly-robust TCP and HTTP load balancer which provides cookie-based persistence, content-based switching, SSL off-loading, advanced traffic regulation with surge protection, automatic failover, run-time regex-based header control, Web-based reporting and management interface, advanced logging to help trouble-shooting buggy applications and/or networks, and a few other features. Its own event-driven state machine achieves 100,000 connections per second and surpasses GigaEthernet on modern hardware, even with tens of thousands of simultaneous connections.
Pound is a reverse HTTP proxy, load balancer, and SSL wrapper. It proxies client HTTPS requests to HTTP backend servers, distributes the requests among several servers while keeping sessions, supports HTTP/1.1 requests even if the backend server(s) are HTTP/1.0, and sanitizes requests.
HTTP Time Protocol is a time synchronization tool that uses Web server responses (HTTP headers) instead of the NTP protocol. If you are behind a corporate firewall, NAT device, or proxy server, HTP will still be able to synchronize the time. For high precision time synchronization, use ntpd.
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.
Cherokee is a very fast, flexible and easy to configure Web server. It supports widespread technologies including FastCGI, SCGI, uWSGI, PHP, CGI, SSI, TLS and SSL encrypted connections, virtual hosts, authentication, on the fly encoding, load balancing, Apache compatible log files, database balancing, reverse HTTP proxy, traffic shaping, video streaming, and much more. A user friendly interface called cherokee-admin is provided for no-hassle configuration of the server. It allows you to configure the server from top to bottom without editing a text configuration file.
HTTPTunnel is a simple client/server application for creating an HTTP tunnel between two machines, optionally via a Web proxy. This tunnel can then be used to wrap arbitrary TCP socket traffic in HTTP, thus allowing communications even through a restrictive firewall that only allows outgoing HTTP connections.
MatrixSSL is an embedded SSL and TLS implementation designed for small footprint devices and applications requiring low overhead per connection. The library is less than 50K on disk with cipher suites. It includes SSL and TLS client and server support, session resumption, and implementations of RSA, AES, 3DES, ARC4, SHA1, and MD5. The source is well documented and contains portability layers for additional operating systems, cipher suites, and cryptography providers.