I used SuperConductor (Dr. Manfred Clynes' program) for a while, but it hasn't yet been updated to handle well in XP and its midi implementation and device handling (none) are not workable as it now stands. (Word is it will eventually get married to Reality and live up to its awesome potential.)

What I loved about SuperConductor that I haven't found anywhere else is its ability to effect a hierarchical pulse. It's kind of like groove quantization, but more subtle and sophisticated. It can make all the difference in the world with a piece. Now I can kludge a simple pulse by using fermatas applied to a staff full of rests in my scoring program, but what I'd really like to have is something that will apply pulse to a midi stream, with the ability to reset the pulse manually at given points.

I looked at one plug-in, that I think may have been called Pulseifier, that made me realize that it will be possible to make a plug-in like this; but Pulseifier doesn't quite do it (the hierarchical thing) as it's now implemented.

If there are any developers out there who might want to take on such a project, please email me: dkistner@treeheart.org. I can paint you a picture of how it should work if you need one. I'd just about kill for a plugin like this.