The Gentoo Linux operating system is a Linux distribution named after the Gentoo penguin. It is designed to be modular, portable, easy to maintain, flexible, and optimized for the user's machine. All tools and utilities are built from source code. For convenience, however, several large software packages are also available as precompiled binaries for various architectures via the Portage system.

OpenSSL is an open source implementation of the SSL and TLS protocols. The core library (written in the C programming language) implements the basic cryptographic functions and provides various utility functions. Wrappers allowing the use of the OpenSSL library in a variety of computer languages are available.

Red Hat, Inc is one of the larger and more recognized companies dedicated to open source software. It is also the largest distributor of the GNU/Linux operating system. Red Hat provides operating system platforms along with middleware, applications, and management solutions, as well as support, training, and consulting services.

Mozilla Firefox is a graphical web browser developed by the Mozilla Corporation, and a large community of external contributors. Firefox, officially abbreviated as Fx or fx and popularly abbreviated FF, started as a fork of the Navigator browser component of the Mozilla Application Suite. Firefox has replaced the Mozilla Suite as the flagship product of the Mozilla project, under the direction of the Mozilla Foundation.

KDE is a free software project which aims to be a powerful system for an easy-to-use desktop environment. The goal of the project is to provide basic desktop functions and applications for daily needs as well as tools and documentation for developers to write stand-alone applications for the system. In this regard the KDE project serves as an umbrella project for many standalone applications and smaller projects that are based on KDE technology, such as KOffice, KDevelop, Amarok and K3b.

MySQL is a multithreaded, multi-user SQL database management system (DBMS) which has, according to MySQL AB, more than 10 million installations. MySQL is owned and sponsored by a single for-profit firm, the Swedish company MySQL AB, which holds the copyright to most of the code base.

The SUSE Linux distribution was originally a German translation of Slackware Linux. The Slackware distribution (maintained by Patrick Volkerding) was initially based largely on SLS. In mid-1992, Softlanding Linux System (SLS) was founded by Peter MacDonald, and was the first comprehensive distribution to contain elements such as X and TCP/IP.

OpenLDAP Software is a free, open source implementation of the Lightweight Directory Access Protocol (LDAP) developed by the OpenLDAP Project. It is released under its own license called the OpenLDAP Public License. LDAP is a platform-independent protocol. Several common Linux distributions include OpenLDAP Software for LDAP support.

The GNU Compiler Collection (usually shortened to GCC) is a set of programming language compilers produced by the GNU Project. It is free software distributed by the Free Software Foundation (FSF) under the GNU General Public License (GNU GPL) and GNU Lesser General Public License (GNU LGPL), and is a key component of the GNU toolchain. It is the standard compiler for the free software Unix-like operating systems and Apple Mac OS X.

Postfix is a free software / open source mail transfer agent (MTA), a computer program for the routing and delivery of email. It is intended as a fast, easy-to-administer, and secure alternative to the widely-used Sendmail MTA.

Apache is a web server notable for playing a key role in the initial growth of the World Wide Web. Apache was the first viable alternative to the Netscape Communications Corporation web server (currently known as Sun Java System Web Server), and has since evolved to rival other Unix-based web servers in terms of functionality and performance. Since April 1996 Apache has been the most popular HTTP server on the World Wide Web; since March 2006 however it has experienced a steady decline of its market share. As of August 2007 Apache served 50% of all websites.

The Linux kernel is a Unix-like operating system kernel. It is the namesake of the Linux family of operating systems. Released under the GNU General Public License (GPL) and developed by contributors worldwide, Linux is one of the most prominent examples of free and open source software.

Samba is a free software re-implementation of SMB/CIFS networking protocol, released under the GNU General Public License. The name Samba comes from inserting two vowels into the name of the standard protocol used by the Microsoft Windows network file system, "SMB" (Server Message Block). As of version 3, Samba not only provides file and print services for various Microsoft Windows clients but can also integrate with a Windows Server domain, either as a Primary Domain Controller (PDC) or as a Domain Member. It can also be part of an Active Directory domain.

Perl is a dynamic programming language created by Larry Wall and first released in 1987. Perl borrows features from a variety of other languages including C, shell scripting (sh), AWK, sed and Lisp. Structurally, Perl is based on the brace-delimited block style of AWK and C, and was widely adopted for its strengths in string processing and lack of the arbitrary limitations of many scripting languages at the time.

Snort is an open source network intrusion prevention system, capable of performing real-time traffic analysis and packet logging on IP networks. It can perform protocol analysis, content searching/matching and can be used to detect a variety of attacks and probes, such as buffer overflows, stealth port scans, CGI attacks, SMB probes, OS fingerprinting attempts, and much more.

PHP is a reflective programming language originally designed for producing dynamic web pages. PHP is used mainly in server-side scripting, but can be used from a command line interface or in standalone graphical applications. Textual User Interfaces can also be created using ncurses. PHP is a recursive acronym for "PHP: Hypertext Preprocessor".

Squid is a proxy server and web cache daemon. It has a wide variety of uses, from speeding up a web server by caching repeated requests, to caching web, DNS and other computer network lookups for a group of people sharing network resources, to aiding security by filtering traffic. Although primarily used for HTTP and FTP, Squid includes limited support for several other protocols including TLS, SSL, Internet Gopher and HTTPS. The development version of Squid (3.0) includes preliminary IPv6 support.

AWStats is an open source web analytics reporting tool, suitable for analyzing data from Internet services such as web, streaming media, mail and FTP servers. AWstats parses and analyzes server log files, producing HTML reports. Data is visually presented within reports by tables and bar graphs. Static reports can be created through a command line interface, and on-demand reporting is supported through a web browser CGI program. AWStats supports most major web server log file formats including Apache (NCSA combined/XLF/ELF log format or common/CLF log format), WebStar, IIS (W3C log format) and many other common Internet formats.

SpamAssassin is used for e-mail spam filtering based on content-matching rules, which also supports DNS-based, checksum-based and statistical filtering, supported by external programs and online databases. SpamAssassin is generally regarded as one of the most effective spam filters, especially when used in combination with spam databases.

Dnsmasq is a lightweight, easy to configure, DNS forwarder and DHCP server. It is designed to provide DNS and optionally, DHCP, to a small network. It can serve the names of local machines which are not in the global DNS. The DHCP server integrates with the DNS server and allows machines with DHCP-allocated addresses to appear in the DNS with names configured either in each host or in a central configuration file. Dnsmasq supports static and dynamic DHCP leases and BOOTP for network booting of diskless machines.

ClarkConnect is a Linux distribution. The Purpose of ClarkConnect to transform any standard PC into a dedicated firewall and Internet server/gateway. The design of the operating system is derived from Red Hat Enterprise Linux, with optional modules for firewall and LAN servers.

The Multi Router Traffic Grapher or just simply MRTG is free software for monitoring the traffic load on network links. It allows the user to see traffic load on a network over time in graphical form. MRTG is written in Perl and works on Unix/Linux as well as Windows and even Netware systems. MRTG is free software licensed under the GNU GPL.

Clam AntiVirus (ClamAV), is a widely used free antivirus software toolkit for Unix-like operating systems. It is mainly used with a mail exchange server as a server-side email virus scanner. ClamAV is open source software distributed under the terms of the GNU General Public License (GPL).

In computing, rsync is a software application for Unix systems which synchronizes files and directories from one location to another while minimizing data transfer using delta encoding when appropriate. An important feature of rsync not found in most similar programs/protocols is that the mirroring takes place with only one transmission in each direction. rsync can copy or display directory contents and copy files, optionally using compression and recursion.

amavisd-new is a high-performance interface between mailer (MTA) and content checkers: virus scanners, and/or SpamAssassin. It is written in Perl for maintainability, without paying a significant price for speed. It talks to MTA via (E)SMTP or LMTP, or by using helper programs. Best with Postfix, fine with dual-sendmail setup and Exim v4, works with sendmail/milter, or with any MTA as a SMTP relay. For Courier and qmail MTA integration there is a patch in the distributed package.

DansGuardian is an award winning Open Source web content filter which currently runs on Linux, FreeBSD, OpenBSD, NetBSD, Mac OS X, HP-UX, and Solaris. It filters the actual content of pages based on many methods including phrase matching, PICS filtering and URL filtering. It does not purely filter based on a banned list of sites like lesser totally commercial filters.