Just a small comment - I think some Apophysis users object to the pushing forward of UF simply because they like Apo because it is free but are somewhat prejudiced towards UF as it is not :-) As to compatibility - in my opinion the writers of the Apo betas should produce an equivalent beta formula for UF every time they make a change (instead of relying on other formula authors) - that's what I'd do if modifying the Apo source - and all changes should be 100% backwardly compatible in both Apo and UF. When I get chance (and I get fed up of improving my UF 3D formulas) I'll get back to the IFS stuff I was writing for UF and do a flame version of the beta formulas I did previously as well as probably some 3D IFS stuff. I've even got an idea how to use the Inverse IFS method to produce something closer to flames which would allow fast rendering of flames under zooming (paticularly useful for animation).

The Meaning and Purpose of Life is to give Life Purpose and Meaning. http://website.lineone.net/~dave_makin/