ZDFS (ZDoom File System) is a library containing the functionality of GZDoom's virtual file system.
ZDFS may be used under a "modified BSD-like license [sic]". Also see https://github.com/ZDoom/gzdoom/blob/master/docs/licenses/bsd.txt for the original copy.
Also see the /legal directory for other third-party licensing documents, and note that individual files may contain their own licensing terms.
./TRACKING contains the Git commit SHA of the latest relevant commit of GZDoom to which ZDFS is up-to-date.