There were also other operating systems that never made it to what we might call the Acorn mainstream, perhaps because they were never completed, were intended for a specialist audience or non-desktop product, or perhaps because the developer's focus shifted away from ARM processors. There are probably also operating systems that we have never heard of because they form part of another piece of software that runs directly on the hardware.
I'm interested in learning about these missing operating systems, both from a technical perspective and in terms of their impact or the potential impact they would have had. It's easy for people to say that their influence was limited because they are less well known than their competitors, but not all inspiration flows through completed, marketable products; the people who worked on these often went on to do other things. Some of these were/are successful on other platforms.
Here's a list of systems that were officially released with Acorn or post-Acorn (Pace, etc.) products:
- Panos (for the 32016 2nd processor)
- Hydra Multiprocessor Kernel