I did a lot of work with transputers and occam in the 1980s and wrote an OS for a machine that used them. The exposure to the CSP way of thinking was a blessing. occam-2 on the other hand was a little too primitive.
I remember when Inmos marketing came up with "We wanted to make occam the FORTRAN of parallel processing". My response was "You have." (a reference to occam-2 having only static arrays and no concept of a record/struct)
They had a functioning compiler and decided to concentrate on other areas and it's not too uncommon for a languages's compiler to NOT be written in that language. Afterall Rust relies on the non-Rust LLVM.
Same area, many of the same people, but at a different studio, FAME. MSS was a spin off due to various "fights". I did some recording, with Spooner and David Hood, at both places, a few years back. I really liked FAME, the room is fantastic but MSS has a great vibe.
Did some recording there a couple of years back. Not a bad room but the studio itself is mostly a museum these days and our engineer had to do a bit of work to get it functioning well enough for our purposes. In the area there are a number of great studios, e.g. Fame, Nutthouse but MSS is closer to a really, really good fried chicken place!