Are there any open source sprite format?

PNG just plainly sucks. I has no support for animations, timing or delta compression and sequence names. Also, PNG is slow at random access (you have to decompress image before use). Proprietary formats (like Diablo 2 DCC) are much better, but highly specialized for their games: some have no true color, other have no directions.

>>40
Linux has hardware support...
if you reverse engineer DirectX driver and write Linux one.

Haiku supports Mesa 3D
On my OLPC XO-1 Mesa is a little slow, compared to plain frame buffer.