At the time, embedded X86 boards were not really a thing yet so we needed something simple that could run with a COTS PC motherboard.
The major factor was that the licensing for other operating systems was too costly or too restrictive. Anything GPL-based was ruled out by our lawyers. Turning Linux into an RTOS would have forced us to release source code and that wasn't a fight with Legal that anyone had time for.
XINU turned out to be just what we needed. The process limit wasn't a huge problem since we were used to running threads on a single process. Adding networking later turned out to be very easy.
https://www.youtube.com/watch?v=8rHbsCyde1g
At the time, embedded X86 boards were not really a thing yet so we needed something simple that could run with a COTS PC motherboard.
The major factor was that the licensing for other operating systems was too costly or too restrictive. Anything GPL-based was ruled out by our lawyers. Turning Linux into an RTOS would have forced us to release source code and that wasn't a fight with Legal that anyone had time for.
XINU turned out to be just what we needed. The process limit wasn't a huge problem since we were used to running threads on a single process. Adding networking later turned out to be very easy.