The GFAL library was developed by LCG to allow applications to easily access and store files across the grid. It's the underlying library providing much of the functionality to lcg-utils The currently supported protocols are: file for local access, dcap (dCache access protocol) and rfio (CASTOR access protocol).
The corresponding ROOT TFile class is TGFALFile. I have tried to use it but had file ... can not be opened for reading (Invalid argument) problems