For a while in the late 1990s, there was a nominally-open camera OS called Digita. I had a camera that it ran on, and none of the skills to take advantage of it, but I remember someone built DOOM for it so that was neat.

People were writing Digita programs to do things like eat NMEA0183 GPGLL sentences and stuff them into the EXIF tags, because USB wasn't ubiquitous yet and a lot of cameras still had RS232 ports and cameras certainly didn't have native geotagging yet, but someone figured out it would be useful.

It was pretty wild, and I don't know why it flopped.