GTKMathplot is an interactive plotting program based on GTK+ and the Cairo graphics library. It can display bidimensional curves, tridimensional curves, and surfaces from Cartesian or parametric equations describing the mathematical objects you would like to visualize. It is designed to be intuitive for high school students with good mathematical knowledge. University students of engineering, physics, mathematics, or natural sciences should need no explanation at all to start using it proficiently.
QMentat helps you practice mental arithmetic. It uses arbitrary-length fixed point arithmetic, and can handle any size numbers, only limited by the size of your screen (and in the case of division with an integer result, the speed at which the number can be factored). It is also quite configurable, allowing you to tailor the questions to your needs.
Whonix is an anonymous general-purpose operating system based on Virtual Box, Debian GNU/Linux, and Tor. By design, IP and DNS leaks are impossible. Not even malware with root rights can find out the user's real IP/location, because Whonix consists of two (virtual) machines. One machine solely runs Tor and acts as a gateway, called Whonix-Gateway. The other machine, Whonix-Workstation, is on a completely isolated network. Only connections through Tor are possible.
Booktype makes it easier for people and organizations to collate, organize, edit, and publish books. Delivering frictionlessly to print, lulu.com, and almost any ereader, Booktype facilitates collaborative production processes, with no more lost manuscripts, overwritten Word files, awkward wikis, or cumbersome CMSes.
ArduinoPulseGenerator is a simple program for generating pulse sequences using an Arduino. There is an associated GUI that runs on the local computer, or you can simply connect to the Arduino with a serial console (9600 baud) and send it commands. This code has been tested on the ArduinoMega 2560 (timing accuracy ~ ±200 μs) and Arduino Due (timing accuracy ~ ±35 μs); it may work on other Arduino boards.
Tryton Android is an Android client for the Tryton ERP system. It lets you access and edit your enterprise information (accounting, invoice, production, stocks, and more) from your Android terminal. It is a generic client like the gtk client, and should be compatible with all Tryton modules. It also contains an SVG parser for Android.