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Japan tried to build an operating system for the entire world, then the US government intervened
(www.xda-developers.com)
This is a most excellent place for technology news and articles.
According to the article it was royalty free and published open standards, but they do not make any claim to this being an FOSS system.
Per Wikipedia…
It’s not even a software project as we know it. It’s a specification like POSIX, and presumably, anything implementing the spec can be certified if it passes a test suite, like UNIX.