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.
DansGuardian is a Web content filtering proxy that uses Squid to do all the fetching. It filters using multiple methods including, but not limited to, phrase matching, file extension matching, MIME type matching, PICS filtering, and URL/domain blocking. It has the ability to switch off filtering by certain criteria including username, domain name, source IP, etc. The configurable logging produces a log in an easy to read format. It has the option to only log text-based pages, thus significantly reducing redundant information (such as every image on a page).
Music Player Daemon (MPD) is a server that allows remote access for playing music in various formats and managing playlists. It makes a great desktop player with frontend options (Qt, GTK, ncurses, Windows, and Web clients are available). It is also appropriate as a console player that is scriptable, and is especially useful if X is restarted frequently. A set of rapid development tools for clients are being developed and include a C library, Python module, PHP class, Perl module, and Java Class. The goals are to be easy to install and use, to have minimal resource requirements, to be stable and flexible, and easy to interface.
Revelation is a full-featured and secure password manager for the GNOME 2 desktop. It aims to be user-friendly and HIG-compliant, and it is tightly integrated with GNOME. It has several account types which can be grouped in folders, searched, and opened in external applications. It can both test and generate passwords. Accounts are stored in an encrypted file which can be accessed remotely via SSH, FTP, HTTP, WebDAV, and more. It can import and export data files for Password Safe, GPass, Figaro's Password Manager, and others.
LMDBG is a collection of small tools for collecting and analyzing the logs of malloc/realloc/memalign/free function calls. Unlike many others, LMDBG does not provide any way to detect overruns of the boundaries of malloc() memory allocations, as this is not the goal. Like most other malloc debuggers, LMDBG allows detecting memory leaks and double frees. However, unlike others, LMDBG generates full stacktraces and separates the logging process from analysis, thus allowing you to analyze an application on a per-module basis.
e3 is a full-screen, user-friendly text editor with an interface similar to that of either WordStar, Emacs, Pico, Nedit, or vi. It's heavily optimized for size and independent of libc or any other libraries, making it useful for mini-Linux distributions and rescue disks. The assembler version supports Linux, FreeBSD, OpenBSD, NetBSD, Win9x, QNX, Atheos, BeOS, ELKS, and DOS. There is also a separately distributed version written in C which supports some other Unix versions and CygWin. It is also possible to use regular expressions by using child processes like sed. e3 has a built in arithmetic calculator.