"LaFS" is a filesystem that I have been working on since 1999. Yes, that is a long time. It has never been my first priority so I have had to fit it around my work on NFSd and md/RAID and regular bugfixing and such. I have maybe used about 10%-15% of my time on it, so I guess that it getting up to 12-18 months "fill time".
LaFS is a log-structured filesystem. The original goal was to work well with RAID and NFS. That is still much of the goal but I see other value in it as well -- such as working well with Flash storage.
How it compares with NILFS or BTRFS I cannot really say, I haven't looked very closely at either. Maybe I will one day and report here what I find.
Current source code can be found at git://neil.brown.name/LaFS and git://neil.brown.name/lafs-utils, or browse on the web at http://neil.brown.name/git/
