[Wine] Is there Wine-like software for other guest platforms?

[KenJackson]

The wine concept--a compatibility layer that allows running executables compiled for Windows on a Linux or Unix host--is a very useful concept that could reasonably be used to adapt between other platforms.  It's somewhere between running a virtual machine and cross-compiling the application.

Is there anything similar for other (non-Windows) guest platforms?

Right now, I'm specifically trying to run QNX4 software (Watcom compiler) on Linux and/or Windows without using my virtual machine.  But I can see where this would be a valuable capability for a variety of platforms.