Rec of the day

Mandelbulber Gallery
A gallery of 3D fractal landscapes that take my imagination onto some distant planet. Totally fascinating and really beautiful - there are structures that look like they're grown organically, and highly technical ones, and planetscapes that look like they're made of molten metal. I bookmarked that site in case I ever need inspiration for some alien background scenery. :)

I have no idea how exactly that program works. (I mean, in theory I know how fractals work but looking at these pics I find it hard to imagine that these bizarre structures can be the result of mathematical calculations!) Anyway, Mandelbulber is open source; available for download at the link above. No idea how much computer power it needs though.