Antenna, a free and open-source dvb-t (terrestrial digital tv) tuner for linux desktops. Antenna is a full featured tool to see what's going on in the sky. It enables you to scan, watch and record television, radio and services broadcasted on air.
A python-based calculator that uses the Sabine, Norris-Eyring and Fitzroy formulae to calculate the RT60 time of a room with given specifications. Material list from SAE Institute reference.