xremote is a simple tool that lets you grab the mouse and keyboard of another machine and control them with your local mouse and keyboard. It creates a form of remote control of other machines. All mouse- and keyboard-actions on the local machine are forwarded to the remote display.
Xstereograph is a modeller for 3D single image stereograms (SIS). It uses Fabian Januszewski's stereograph renderer to actually produce the stereograms, and includes a powerful GUI and an internal modeller capable of building polyhedra and 3D bodies such as ellipsoids, tori, trefoil knots, etc. There are many samples and examples in the package.