Gri is an extensible plotting program designed for scientists. It can draw x-y plots, contour plots, and image plots, and has rudimentary programming capabilities. Output is PostScript. Gri is not mouse driven, nor GUI-based; it is a language. Users regard it as an analogue to the LaTeX document formatting language: users gain considerable power, at the price of a moderate learning curve.
WMScript is a system monitoring dock app for Window Maker. It allows you to specify a command and have the numeric result of that command displayed in the dock app's window. You may specify up to 5 things to monitor and the interval is configurable. This combines to make it a very flexible tool for system monitoring. It is based on WMiNet, and the look is the same.
PyleWiki is a WikiClone written entirely in Python that allows a group of people to collaboratively edit a tree of webpages using nothing but their browser and a simple, text-based markup language. This particular WikiClone has a few extensions to the original: attachments to pages, user authentication (primitive), and the use of templates for page styling among others.
Mandriva is an RPM-based Linux distribtion. It excels at usability and simplicity, features thoroughly preconfigured KDE and GNOME desktops, and includes cool tools like supermount (transparent access to removable media) and DiskDrake (a full-featured graphical hard-drive partitioner). Unlike former versions, Mandriva is not a tuned-up Red Hat, but a very mature Linux distribution on its own. Mandriva is published by a company, but is a completely open and transparent free-software project.