ibcs-us
Linux user-space emulator SCO, Sun, Xenix and others
...It is the same thing implemented in user-space. iBCS64 is a fork of https://sourceforge.net/projects/linux-abi/ that ported it to amd64.
All available documentation can be read online at http://ibcs-us.sourceforge.net/
In summary: if you run "ibcs program args", where "program" is a statically linked binary (elf, coff, elf) that ran on Xenix, SCO SVR4, SVR4, wyse or similar operating system, there is a chance it will run under Linux.
If it doesn't run you can probably get it to run if you have a platform it does run on and know C. ...