OpenAFS是一套开放源代码的分布式文件系统。它能让系统之间通过局部和广域网络来分享档案和资源。OpenAFS以AFS 3.6源代码为基础，其版权宣告采用IPL（IBM 公用授权），因为某些技术和版权上的理由，IBM无法将AFS完整源代码释出，因此另外推出一套商业版本，提供商业支持服务的IBM AFS。Open AFS的任何发展成果可能会带入IBM AFS，但反之则否。另外，IBM并不提供Open AFS 的商业支持服务。

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 file sharing, providing location independence, scalability, security, and transparent migration capabilities for data.

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.