>>Sadly KoanPro has not been actively developed for over five years
now but it's definitely still worth checking out. It's a very deep
programme. And it is most definitely interactive - at least it can
react in a greater or lesser degree to midi input. But it has one major
weakness: no midi clock sync.<<
I was describing koan to someone just the other day.... I used to play with it a lot, though I found it almost frustratingly overwhelming in the possibilities it offered for setting rules & so forth. my copy said it had midi clock in/out, but it was greyed-out, like it was a demo version or something. this wasn't a demo copy though- I remember becoming a registered user. shame. you need a geet big screen too.
I'd finally get the thing doing something I recognised as musical (whatever that means), & then set it back to the start with the intention of letting it rerun the piece into a recorder... it would always set off in a completely different direction. you had to record everything it did & splice it together afterwards.
it was like being taken on a field-trip through some fantastic country by a five-year-old savant, when I guess what I wanted was an intellectual equal who'd do what I told them to.
so I started a band instead.... :-)