I think if you change a fractal - be it Apo, UF or anything else - so that it is unrecognisable from the original then you should be at liberty to call it your own. However if your parameters can still be recognised in other people's flames, then I think they certainly owe you an acknowledgement - if you require one. I have starter flames for free download on my website (for some reason they couldn't accept them here in the Free Stuff section although I know they download OK because I have spoken to people who use them) When I say free, I mean exactly that, there are no strings, I don't want any acknowledgement - if I felt the need for someone to acknowledge me every time they used one I wouldn't give them away in the first place, I'd use them myself! However, unless it is made perfectly clear that no acknowledgement is required I think it should be given as a courtesy if, as I say above, the original parameters can still be recognised. This is always a contentious issue - when is an image truly yours - but I think people should always look at the intent behind it - did someone really try to 'steal' your original and claim it as their own or was it just a helpful basis for them to start their own creation. Well my twopennyworth has developed into nearly 1 so I guess I'll get off my soapbox! M

We don't cease to play because we grow old, we grow old because we cease to play.