This Fortran interface for reading xdr files (both xtc and trr formats) is based on the work of James 'Wes' Barnett and depends on the XTC Library.
Barnett's original interface was made only for xtc files. His code and the explanatory article are available on James 'Wes' Barnett's blog (the blog has been removed). Inspired by Barnett's well-designed interface, I modified it to incorporate the trr format.