FSL is described as 'comprehensive library of analysis tools for FMRI, MRI and DTI brain imaging data. It runs on Apple and PCs (both Linux, and Windows via a Virtual Machine), and is very easy to install'. There are four alternatives to FSL for a variety of platforms, including Linux, Windows, Android, Android Tablet and iPad. The best alternative is BrainExpress. It's not free, so if you're looking for a free alternative, you could try OpenVibe. Other great apps like FSL are NeuroRT Studio (Paid) and Turbo-BrainVoyager (Paid).