FMRIB Software Library software (FSL)

[http://www.fmrib.ox.ac.uk/fsl FSL] is a package for analysis of FMRI, structural, and diffusion data. FSL is written by the [http://www.fmrib.ox.ac.uk/analysis image analysis group] at [http://www.fmrib.ox.ac.uk Oxford Centre for Functional Magnetic Resonance Imaging of the Brain]. The package is mostly C or C++ with a Tcl/Tk GUI, and has a dual license - open source and free for academic use, but commercial use requires a paid license.