Boxes is a text filter that can draw any kind of box around its input text. Box design choices range from simple boxes to complex ASCII art. A box can also be removed and repaired, even if it has been badly damaged by editing of the text inside. Since the generated boxes may be open on any side, the program can also be used to create regional comments in any programming language. New box designs of all sorts can easily be added and shared by appending to a free format configuration file. In addition to being a command line tool, Boxes integrates well with any text editor that supports filters.
Genius is an arbitrary precision integer and multiple precision floating point calculator. It includes its own programming language similar in some aspects to C, bc, or Pascal. It can deal with rational numbers and complex numbers. It has matrix support as well. It uses the gmp library so it is very fast for calculations of large numbers. It has a command line and a GNOME interface. The GNOME interface supports plotting functions and 3D surfaces.
HEYU provides a command line interface to communicate with the CM11A hardware module from X10. The CM11A will send remote control signals over the power lines to remote modules within your house. HEYU can be run from cron to automate lights, sprinklers, etc., or can store macros and timers in the CM11A memory for standalone operation. Auxiliary input is supported from MR26A, W800RF32A, and RFXCOM X10 RF receivers for X10, X10 Security, RFXSensor, RFXMeter, Oregon, and DigiMax RF signals (subject to the capabilities of the receiver). Arbitrary commands and scripts can be launched based on X10 and RF signals and the state of the system. HEYU also supports the CM17A "Firecracker" device for transmission of X10 RF signals.
integrit is an alternative to file integrity verification programs like tripwire and aide. It helps you determine whether an intruder has modified a computer system. integrit's major advantages are a small memory footprint and simplicity. It works by creating a database that is a snapshot of the most essential parts of your computer system. You put the database somewhere safe, and you can then use it to make sure that no one has made any illicit modifications to the computer system. In the case of a break in, you know exactly which files have been modified, added, or removed.
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.
kgrep searches through a file or files for a specified pattern and displays the target line containing the pattern as well as a certain number of lines on either side of the target line. GNU grep can do this with the -A, -B and -C switches, and other platform-specific grep implementations may have similar functionality. The main advantage to kgrep is that it's small and can be easily used on any system that has Perl5 installed, rather than going through the hassle of installing a different grep binary (this is actually what the author uses it for most often).
LCDproc is a utility to drive one or more LCD (and LCD-like) devices attached to a host. It is comprised of a server, which uses a modular device driver system to control attached displays, and one or more clients to gather data as appropriate and send screen data to the server. The included client displays a multitude of system statistics (CPU/memory/disk usage, uptime, date and time, temperature, etc.). Multiple clients can connect to the server simultaneously, and clients can set priorities on the screens they provide to influence in what order items are displayed. This facility can also be used to "pop" critical screens (such as an entry from syslog from a log-watching client). All functionality is implemented in userland. Support for many display devices and several platforms (Linux, *BSD, and Solaris at least) is included.