The X11 Work Bench, an IDE for working on X11 applications, with a simple C language toolkit that should be familiar and easy to use for old school GUI programmers (currently pre-alpha state)
Ethernet to MIDI bridge using libfluidsynth
A serial comms command line utility that is primarily intended for customized command and control of a device via a serial port. Originally written to do 'calibration' commands for an Arduino-based device, hence the name 'sftardcal'. Targeted for POSIX (Linux, BSD) systems and MS Windows (command line only).