While S3 Texture Compression (S3TC) is widely used by many
games and applications since its inclusion into OpenGL 1.3 and Microsoft
DirectX 6.0, these lossy texture compression algorithms have not been
implemented in the open-source Linux graphics drivers. This lack of
open-source support is due to S3 Graphics holding the patent rights to
this technology that they actively license to major hardware vendors.
There long has been an external library that can be loaded and will work
with most Mesa / Gallium3D drivers for advertising S3TC support, but
it's not found by default and it's not included in leading Linux
distributions due to these legal fears. There may now be a new solution
for the S3TC Linux problem thanks to the advent of a new (and simpler)
texture compression algorithm that can serve as a drop-in replacement.