Part of our business-critical financial analytics software was running on VAX/VMS, then AlphaVMS decades ago. Written in DEC Pascal (let's just say - not really compatible with any other Pascal dialects I am aware of). We managed to port the whole system to Linux (before Linux became fashionable) by a godawful contraption made of Scheme, Perl, shell and elisp - it "translated" the Pascal code into a dialect understood by p2c, which in turn translated it to C. That was mucho fun!