While the Reiser4 file-system has been in development for the better part of the past decade, it still hasn’t been merged into the mainline Linux kernel. Reiser4 is still out-of-tree, doesn’t see much new development activity by its limited developers, and the file-system remains tarnished due to its founder, Hans Reiser, being a convicted murderer. However, Edward Shishkin the former Namesys employee, does continue to drive its development forward. Reiser4 was recently updated to work with the more modern Linux 3.5 kernel.
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