John the Ripper is a fast password cracker, currently available for many flavors of Unix, Windows, DOS, BeOS, and OpenVMS. Its primary purpose is to detect weak Unix passwords. It supports several crypt(3) password hash types commonly found on Unix systems, as well as Windows LM hashes. On top of this, lots of other hashes and ciphers are added in the community-enhanced version (-jumbo), and some are added in John the Ripper Pro.
The GNU Gatekeeper is a free H.323 gatekeeper based on the OpenH323 project. You can use it to manage a Voice-over-IP network and let endpoints (e.g., Netmeeting) communicate through symbolic names. It also has an external interface for billing and other applications. It runs on a number of Unix versions (including Linux and Solaris) and Windows.
The j661 project provides a generic CDS (or ARINC 661 Server) in order to facilitate the understanding of the ARINC 661 standard, prototype ARINC 661 concepts and architectures, and facilitate the reuse of ARINC 661 specifications and artefacts between projects. The CDS architecture is designed to allow defining the Server behavior to be easily modified or extended. This is achieved by a modular plug-in architecture, allowing customization at runtime without changing anything in the Server core itself.
NetXMS is a network monitoring and management system with a modular architecture. It can be used for monitoring an entire IT infrastructure, starting with SNMP-capable hardware (like switches and routers) and ending with applications on servers. The system has a three-tier architecture; the information is collected by monitoring agents (either its own agents or SNMP agents) and delivered to the monitoring server for processing and storing, where it can be accessed by using the management console. It features centralized configuration and centralized agent upgrades.
Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.
Dar is a shell command that makes backup of a directory tree and files. Its features include splitting archives over several files, DVD, CD, ZIP, or floppies, compression, full or differential backups, strong encryption, proper saving and restoration of hard links, extended attributes, file forks, Door inodes, and sparse files, remote backup using pipes and external commands (such as ssh), and rearrangement of the "slices" of an existing archive. It can run commands between slices, before and after saving some defined files or directories (for a proper database backup, for example), and quickly retrieve individual files from differential and full backups. Several external GUIs exist as alternatives to its CLI interface, like kdar, DarGUI, SaraB, etc.