In my last post I said that the anti-fragmentation code was reducing performance in the upcoming substantially. That was due to a bug, now fixed. So release 5 should have full planned features with full performance.
release1: initial version
release2: more flexibility, more benchmarks
release3: improved benchmark report format, some minor fixes & tweaks
release4: many bugfixes, more benchmark report format changes
release5: (not out yet) added optional anti-fragmentation code which currently has an unfortunately large performance impact