Freesurfer
Freesurfer is a an open source neuroimaging toolkit for processing, analyzing, and visualizing human brain MR images. Freesurfer is developed by the Laboratory for Computational Neuroimaging at the Athinoula A. Martinos Center for Biomedical Imaging.
Official resources
References
If you use Freesurfer in your research, use the dedicated page to cite the relevant publication(s).