I need to run 1 Windows app on my system and there's no Mac alternative.
However, installing a Virtual Machine or Boot Camp partition seems overkill for just one single app. Are there any other ways to run the app on my system?
Try Virtual box, its a competitor to vmware/parallels. The advantage over those two are that its free. You just need to supply windows (as you would with vmware/parallels)
Wine may work but the compatibility list is woefully short. Your only viable option is to run a version of windows either in virtualization or bootcamp
Darn I was going to say WINE! I researched WINE thinking it was only for Linux, but it turns out its for Mac OS X as well. As far as I know you could X11, but I know almost noting about it.
This is what I use too. It has worked on most applications I have tried it with. But these are mostly just simple apps that don't require installers or anything, not sure how it would handle a game or something similar.