[hDeraj]

This is actually a bug with CSS3D transforms in general with Firefox:

http://jsfiddle.net/yNfQX/21/

[robin_reala]

This is being tracked at https://bugzilla.mozilla.org/show_bug.cgi?id=1187209

[nothis]

Looks like this jsfiddle just doesn't do per-pixel z-sorting (which I wouldn't have expected from browser 3D effects) but in my brain that shouldn't be an issue with cubes (no polygons overlapping).

[thenomad]

That's depressing. This is a really neat bit of tech that I'd never consider using whilst it doesn't work in FF...