Fusion runs Windows, which runs any Windows program. Crossover only runs a subset of Windows applications. If you want to be able to run anything, then Fusion works great, although you do need a Windows license. Crossover runs without Windows, so you may save some money, but you only get to run what Crossover supports. I have a Windows license so I chose Fusion for those times I need to run a Windows app. It's working well for me.