Kamoso is a utility that does the very simple actions a webcam offers, like taking pictures or recording videos and adds some extra features that will make the webcam usage both funnier and more useful.

Enemylines 3 is a single-player game. You have to shoot evil robots before they get too close, you can use your jetpack to escape. The robots can't jump but they tear down walls.

Cowsay (or cowthink) will turn text into happy ASCII cows, with speech (or thought) balloons. If you don't like cows, ASCII art is available to replace it with some other creatures (Tux, the BSD daemon, dragons, and a plethora of animals, from a turkey to an elephant in a snake).

Referencer is a GNOME application to organise documents or references, and ultimately generate a BibTeX bibliography file. Referencer includes a number of features to make this process easier:

KmPlot is a powerful mathematical plotter KDE, capable of plotting multiple functions simultaneously and combining them into new functions.