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.
Snort is a network intrusion detection and prevention system. It is the most widely deployed technology of its kind in the world. It performs detection using a variety of methods including rules-based detection, anomaly detection, and heuristic analysis of network traffic. Its rules language is open source and available to the public as well.
GKrellM is a GTK-based stacked monitor program that charts SMP CPUs, disks, load, active net interfaces, and internet connections. There are also builtin monitors for memory and swap, file systems with mount/umount feature, mailbox checking including POP3 and IMAP, clock/calendar, laptop battery, sensors (temperatures, voltages, and fans), and uptime. It has LEDs for the net monitors and an on/off button and online timer for PPP. There is a GUI popup for configuration, plugin extensions can be installed, and many themes are available. It also features a client/server monitoring capability.
PHP Content Management System (phpCMS) makes it possible to need only one template for your whole Web site. It allows you to provide dynamic menus with unlimited levels, and use templates and sub-templates without a database. It is search engine-friendly and proxy-friendly, as the pages it generates can not be distinguished from static HTML pages. PHP code can be added to any template and content file with an optional module. It supports the caching of parsed pages and gzip compression.
gnokii is a multisystem tool suite for mobile phones. It provides a library to communicate with a phone hiding the communication protocol. The library handles SMS, phonebook, calendar, phone calls, and other mobile phone capabilities. It supports Nokia-FBUS mobiles, AT-capable phones (most of the mobiles), as well as Symbian-based phones.
nxlog is a modular, multi-threaded, high-performance log management solution with multi-platform support. In concept, it is similar to syslog-ng or rsyslog, but is not limited to Unix/syslog only. It can collect logs from files in various formats, receive logs from the network remotely over UDP, TCP, or TLS/SSL on all supported platforms. It supports platform-specific sources such as the Windows Eventlog, Linux kernel logs, Android device logs, local syslog, etc. Writing and reading logs to/from databases is also supported for many database servers. The collected logs can be stored into files, databases, or forwarded to a remote log server using various protocols. The old BSD Syslog and the newer IETF syslog standard (RFC 3164 and RFC 5424-5426) are fully supported by nxlog in addition to XML, JSON, CSV, GELF, and other custom formats. A key concept in nxlog is to be able to handle and preserve structured logs so there is no need to convert everything to syslog and then parse these logs again at the other side. It has powerful message filtering, log rewrite, and conversion capabilities. Using a lightweight, modular, and multi-threaded architecture which can scale, nxlog can process hundreds of thousands of events per second.
Freeciv is a multiuser reimplementation for Unix/X of the famous Microprose game of Civilization. By default, the game is an improved Civ II, but this can be customized; modpacks for near-100% compatibility with Civ I and Civ II are included. Multiuser gameplay is real-time: in each turn, all human players move concurrently. The game is designed to remain fairly playable even on poor network connections. Freeciv can also be played on standalone machines, and its AI players are a good challenge for beginners. The source code comes with the server, two X clients, and non-X clients for MS Windows and Amiga. Freeciv is released under the GNU General Public License. It is maintained by an international team of coders and enthusiasts, and is easily one of the most fun and addictive network games out there.
Ettercap is a network sniffer/interceptor/logger for ethernet LANs. It supports active and passive dissection of many protocols (even ciphered ones, like SSH and HTTPS). Data injection in an established connection and filtering on the fly is also possible, keeping the connection synchronized. Many sniffing modes were implemented to give you a powerful and complete sniffing suite. Plugins are supported. It has the ability to check whether you are in a switched LAN or not, and to use OS fingerprints (active or passive) to let you know the geometry of the LAN.