Managing Filesystem VersionsJason C. Young,Rajagopal Ananthanarayanan,Randal C. Burns,Darrell D. E. Long,Robert M. Rees,Ralph A. Becker-Szendy,James J. Seeger,David M. WolfeU.S. Patent 7,139,781November 2006View at Google PatentsDescriptionA comprehensive system for managing multiple versions of files within a file system.