AFS is a distributed filesystem product, pioneered at Carnegie Mellon University and supported and developed as a product by Transarc Corporation (now IBM Pittsburgh Labs). It offers a client-server architecture for federated file sharing and replicated read-only content distribution, providing location independence, scalability, security, and transparent migration capabilities. AFS is available for a broad range of heterogeneous systems including UNIX, Linux,  MacOS X, and Microsoft Windows

IBM branched the source of the AFS product, and made a copy of the source available for community development and maintenance. They called the release OpenAFS.

via OpenAFS.