The most recent changes are at the top of this file. 2007-06-17 Made sure loops were truely asynchronous. The problem here is that to do this takes more time and hurts performance. For the tightest loop (mkLoopS $ SendS IntS), this makes performance 2.5 times worse, which isn't surprising when you consider the change in the number of MVars accessed each time through the loop. The fix here was quite different to how I'd imagined it (and documented in the paper). 2007-06-14 Initial release. Cabalised and uploaded to Hackage.