I just came across this line in the manual, under "Publish" ...
"The source code for acknex.exe is available in the engine SDK. You can create your own executable as long as you provide a machine readable copy of the full source code along with the product. P If you own the Pro Edition or a SDK license, you don't need to provide the source code."

Obviously it's a huge undertaking, but any engine programmers out there could probably have some fun trying to get the engine to run on Linux or some other OS