Linux is a clone of the Unix kernel, written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. It aims towards POSIX and Single UNIX Specification compliance. It has all the features you would expect in a modern fully-fledged Unix kernel, including true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management, and TCP/IP networking.
PostgreSQL is a robust relational database system with over 25 years of active development that runs on all major operating systems. It is fully ACID compliant, and has full support for foreign keys, joins, views, triggers, and stored procedures (in multiple languages). It includes most SQL92 and SQL99 data types, including INTEGER, NUMERIC, BOOLEAN, CHAR, VARCHAR, DATE, INTERVAL, and TIMESTAMP. It also supports storage of binary large objects, including pictures, sounds, or video. It has native programming interfaces for C/C++, Java, .Net, Perl, Python, Ruby, Tcl, and ODBC, among others, and exceptional documentation.
Tiki Wiki CMS Groupware is a full-featured, Web-based, multilingual, tightly integrated, all-in-one wiki, CMS, and groupware. Tiki can be used to create all kinds of Web applications, sites, portals, knowledge bases, intranets, and extranets. Tiki offers a very large number of features "out-of-the-box". It is highly configurable and modular. All features are optional and administered via a Web-based interface. Major features include a robust wiki engine, news articles, discussion forums, newsletters, blogs, file and image galleries, bug and issue trackers, a link directory, polls/surveys and quizzes, FAQs, a banner management system, calendar, maps, mobile access, RSS feeds, a category system, tags, an advanced themeing engine (Smarty), spreadsheet, live support, shoutbox, inter-user messaging, menu generator, advanced permission system for users and groups, internal search engine, external authentication support, and more. It was formerly named TikiWiki.
Clonezilla is a partition or disk cloning tool similar to Symantec Ghost. It saves and restores only blocks in use on the hard drive if the file system is supported. For unsupported file systems, dd is used instead. It has been used to clone a 5 GB system to 40 clients in about 10 minutes.
fio is an I/O tool meant to be used both for benchmark and stress/hardware verification. It has support for 13 different types of I/O engines (sync, mmap, libaio, posixaio, SG v3, splice, null, network, syslet, guasi, solarisaio, and more), I/O priorities (for newer Linux kernels), rate I/O, forked or threaded jobs, and much more. It can work on block devices as well as files. fio accepts job descriptions in a simple-to-understand text format. Several example job files are included. fio displays all sorts of I/O performance information, including complete IO latencies and percentiles. Fio is in wide use in many places, for both benchmarking, QA, and verification purposes. It supports Linux, FreeBSD, NetBSD, OS X, OpenSolaris, AIX, HP-UX, and Windows.
LiVES is a simple to use yet powerful video effects, editing, conversion, and playback system aimed at the digital video artist and VJ. It runs under Linux, BSD, Mac OS X/Darwin, IRIX, and openMosix. It is frame and sample accurate, can handle almost all types of video, and is fully extendable through plugins and the included plugin builder tool. It can also be controlled remotely using OSC.
Lynis is an auditing and hardening tool for Unix derivatives like Linux/BSD/Solaris. It scans systems to detect software and security issues. Besides security-related information, it will also scan for general system information, installed packages, and possible configuration mistakes. The software is aimed at assisting automated auditing, software patch management, and vulnerability and malware scanning of Unix-based systems.