Comment by miki123211

This is missing large parts of the story.

Microsoft only bought the speech recognition / med tech parts of nuance, everything else, notably the Vocalizer speech stack (and likely also Eloquence) was spun off as Cerence. We know that somebody still has source code for Eloquence somewhere, as Apple licenses it and compiles it natively for aarch64 (yes I've looked at those dylibs, no there's no emulation). Not sure why nobody is recompiling the Windows versions, either there's just no need to do so, or some Windows specific part of the code was lost in all the mergers and would need to be rewritten.

A lot of Eloquence IP was also licensed by IBM, and the text-to-phoneme processing stuff is still in use for IBM Watson to some extend (it's vulnerable to the same crash strings and has similar pronunciation quirks).

With that said, I'm not sure if Eloquence system integrators are getting the Delta code and the tools to compile it to C++, or just the pre-generated cpp. Either would be consistent with the fact that Apple compiles it for their own platforms but doesn't introduce any changes to the pronunciation rules. It is entirely within the realms of possibility that this part of the stack has been lost, at least to Cerrence, though there's nothing that specifically indicates that such is the case.