- Arduino - Microcontroller. This can be useful for building props that have to be able to do a certain thing on cue, or it can be used as part of a cue light system or a few million other things. Some electronic design experience is needed, but there's a massive user base with literally millions of tutorials and development kits and other ways to learn how to put it to use.
- Raspberry Pi - A small, cheap 1.5GHz computer. It features 3.5mm audio, HDMI, 4 USB ports, ethernet, wifi and bluetooth. Great for dedicated computer functions like video playing.
- Enttec DMX USB Controllers - DMX to USB adaptars. Available for cheap and expensive.