Parallel Virtual File System, Version 2 - The next generation of Parallel Virtual File System. Source code, documentation, and mailing list. - http://www.pvfs.org/
Global File System - A shared disk cluster filesystem for Linux that supports journaling and failure recovery. Source code, documentation, papers, and mailing list. - http://www.redhat.com/software/rha/gfs/
IBM: GPFS - General Parallel File System for AIX. - http://www.almaden.ibm.com/StorageSystems/file_systems/GPFS/
RS/6000 SP Books: GPFS - Documentation and papers. - http://www.rs6000.ibm.com/resource/aix_resource/sp_books/gpfs/index.html
Parallel Virtual File System - A parallel file system for Linux clusters. Source code, manual, and papers. - http://parlweb.parl.clemson.edu/pvfs/
The Galley Parallel File System - A filesystem designed for parallel computers. Description of file structure, papers, and source code. - http://www.cs.dartmouth.edu/~nils/galley.html