What is "openzfs"

The OpenZFS is an umbrella project aimed at bringing together individuals and companies that use the ZFS file system and work on its improvements, aiming as well at making ZFS more widely used and developed in a true open-source manner.

OpenZFS brings together developers from the illumos, Linux, FreeBSD and OS X platforms, and a wide range of companies. High-level goals of the project include raising awareness of the quality, utility and availability of open-source implementations of ZFS, encouraging open communication about ongoing efforts toward improving open-source variants of ZFS, and ensuring consistent reliability, functionality and performance of all distributions of ZFS.

Illumos, which derived from OpenSolaris, provides upstream source code for other ZFS implementations. While there are various differences between the illumos ZFS codebase and other open-source implementations of ZFS, OpenZFS is strategically reducing existing platform-related differences in order to ease sharing of the source code.

Founding members of OpenZFS include Matt Ahrens, one of the main architects of ZFS.