Where is the source code?
There is no central source repository for OpenZFS. Each supported operating system has it's own repository.
|ZFS on Linux||Webpage||Github|
Even though the core of OpenZFS is platform independent, separate repositories are necessary because significant platform-specific changes need to be maintained for the parts of ZFS which interact with the rest of the operating system (VFS, memory management, disk i/o, etc.). Platform-independent changes are regularly ported between the different operating systems. One of our goals is to more clearly separate the platform-dependent from platform-independent parts of OpenZFS to make porting changes easier.
Are storage pools created by OpenZFS portable between operating systems?
Yes. Storage pools can be moved freely between the different implementations of OpenZFS as long as all implementations involved support the same feature flags. New feature flags are usually ported to all operating systems very quickly to maintain compatibility. Storage pools can also be created with certain feature flags disabled to maintain compatibility.
Is this a re-implementation of ZFS?
OpenZFS is a fork of ZFS on Solaris based on the last release of OpenSolaris from 2010. Source code changes to Solaris have not been released since 2010, so development of OpenZFS has continued completely separately from ZFS on Solaris. Each now has features the other does not. The on-disk formats of ZFS on Solaris and OpenZFS have also diverged, unless you explicitly create storage pools with format version 28 (the last version released with OpenSolaris) ZFS pools cannot be moved between OpenZFS distributions and ZFS on Solaris.
Will OpenZFS ever be released under a licence other than the CDDL?
No single entity holds the copyright to all of the OpenZFS code, every individual contributor to OpenZFS maintains copyright to his or her changes. This means that changing the license would require participation from all contributors which makes it highly unlikely.