"We last talked about Tux3 file-system in September and just
this past week the project's Daniel Phillips has shared a progress
report. Up until recently, work on the Tux3 file-system was done as
a Linux FUSE module, but work is well underway in a kernel port for
Tux3. For those unfamiliar with this promised file-system, it's a
successor to the never-released Tux2 is a write-anywhere, atomic
commit, btree-based versioning file-system."