Whamcloud invests a huge amount of time and resources into ensuring that every release is high quality. However, Whamcloud recognizes that many Lustre users would rather run a release that is well-proven in production even if it means foregoing some of the newer features. To meet the needs of these customers, Whamcloud designates a certain release to be its stability release stream and produces regular bugfix only updates for this release. These releases are what the majority of Whamcloud's customers choose to run in production.
Whamcloud is continually developing new features required by future versions of Lustre. Users who want to use these capabilities can access them first in feature releases. Periodically a new feature release will be designated the new stability release stream.
For the current plans for both stability and feature releases, please see the Lustre Roadmap