The same discussion again and again...

> And also they have a fast software rendering framework (Pixman) that doesn't require running a full optimizing compiler at runtime (LLVM) and is relatively simple.

The thing is, the future of accelerated graphics on Linux (Gallium3D) already requires something like LLVM to compile hardware-agnostic shader code into binaries which can run on the GPU. It also requires CPU-based fallbacks for operations (shader code) which the GPU doesn't support efficiently. The llvmpipe software renderer is basically just a plain Gallium3D driver which relies exclusively on the fallbacks.

"Simpler", in this case, means taking advantage of the common CPU fallback code to provide a full-featured graphics driver, not relying on a completely separate software-only rendering framework with fixed primitive operations which can only be accessed via Cairo.

Due to the modularity of LLVM, much of the effort expended on optimized code generation for the x86 backend can probably be reused for various GPU backends down the road.