A free, open-source, multi-platform application for sending files and messages, using the codec2 HF modems.
A wiki dealing with television watching and recording using Linux and F/OSS software.
A suite of open source electronic design tools. Uses a GUI for schematic capture. Also capable of analog and digital simulation, generation of parts lists and export of PCB designs for fabrication.
William Gibson's self-destructing work Agrippa has been reconstructed from one of the original diskettes (it was never actually released) and put online as a simulation.