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.
G4L is a hard disk and partition imaging and cloning tool. The created images are optionally compressed, and they can be stored on a local hard drive or transferred to an anonymous FTP server. A drive can be cloned using the "Click'n'Clone" function. G4L supports file splitting if the local filesystem does not support writing files larger than 2GB. The included kernel supports ATA, serial-ATA, and SCSI drives. Common network cards are supported. It is packaged as a bootable CD image with an ncurses GUI for easy use.
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.
SubnetMapper is an admin's quick tool to map and keep track of managed IP networks, track free ranges that are available for assigning, and document the network setup. It has been designed to help admins manage and document small to medium networks. It prints and displays freely colorable maps of your network.
Trojan scan is a simple shell script that allows for simple but relatively effective checking for trojans, rootkits and other malware that may be using your server and network for unwanted (and possibly illegal) purposes. It works by listing all processes that use the Internet with the lsof command (using -Pni flags). This list is then transformed into signatures in the form of process_name:port_number:user. These signatures then are matched against the allowed process defined in the configuration. If any signatures of running processes are found that do not match the allowed signatures, an email report is sent including ps, ls, and optional lsof output.
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.
MacPorts makes the world of open source software available to your Mac. There are over 5600 software titles ("ports"), each one installable with a single command. This is probably the biggest, most up to date open source software collection for Mac OS X. MacPorts works much like the ports collections of the major BSD operating systems.