Wine
Porting an app to Linux with Wine

Wine can run any app... if you want it bad enough

The first step is free: use the app daily under Wine, and file bugs at winehq for any problems you find.  Include a recipe for how to reproduce it!

Easy to reproduce bugs often fixed by volunteers

Otherwise you can hire someone to fix them
fixing 2-3 bugs: $5K
implementing major new functionality: $50K and up