It used to be http://obo.cvs.sourceforge.net/viewvc/obo/obo/ontology/anatomy/cell_type/ (/obo/obo/) but now http://obo.cvs.sourceforge.net/viewvc/obo/obo/obo/ontology/anatomy/cell_type/ (/obo/obo/obo)
SAME - for GO, PATO, maybe more...