[anthk]

Pre BSD's (386BSD) where in the same case with AT&T Unix and after a few years of rewritting code under BSD licenses they were perfectly ok to ship, from NetBSD 0.9 to FreeBSD, OpenBSD was a NetBSD fork.

Current OpenTTD has no former TTD code since decades ago. I remember Solene@ from OpenBSD (now ex-user) playing OpenTTD for MacPPC (PowerPC G4) a few years ago as she had in issue with mouse input.

Good luck running decompiled X86 code as is.