Nall is a small status icon application that discreetly fits into the system tray. Its purpose is to spawn a list of user scripts periodically and display one line of output per script in a tooltip window. Thus, it is possible to "monitor" any kind of event that can be detected with a script. Nall does not care about the return values of the scripts it runs, but only displays their output. It is also easy to interface nall with Nagios plugins.
Seetxt is a lightweight text file and man page viewer for X windows. It maintains "document meta-data" for each user, allowing them to automatically keep bookmarks and highlights for read-only system files. It also has a "server mode" so that command line requests can be sent to a single running server rather than starting multiple instances. Other features include hypertext-style apropos (man page) searches, file monitoring, multi-level regular expression searching, a command history, and nice little toggle lights on the interface for the server and file monitor. There's also cross-application drag-n-drop support, and handy little features that allow you to view the output of shell commands and process the text buffer with an external command (sed, awk, grep, perl, etc.) Seetxt is POSIX compliant.
clac (Command Line Advanced Calculator) evaluates mathematical expressions input via command line arguments or from stdin and writes the results to stdout. Unlike other command line calculators, clac has infix (natural order) expression syntax, is quite comfortable with complex numbers, defines a great many functions and constants by default, and allows easy definition of new user functions and constants using Python.
Vis/Space is a client-server system for visually exploring data structures in 3D virtual space. It allows the placement of various data sources in a three-dimensional environment. Custom search terms can be entered into a query field, or can be navigated to and from an existing object. All objects like images and "text screens" can be moved around. A single click on an image shows the full-resolution version in the foreground. Whole collections of images can be moved. A click to the cube also toggles among several different possible layouts. Data sources include search engines, microblogging, Wikipedia, image/video search, and 4chan.
HDT (Hardware Detection Tool) is an OS independent tool that displays low-level information on any x86 compatible system. It detects ACPI, CPU, PCI devices, DMI (memory, BIOS, motherboard, IPMI base board, chassis, batteries, CPU), disks (geometry, partitions), PXE environment, VESA modes, and VPD. It can also deduce the Linux kernel modules needed by a given host.