Both fed user-written GLSL to the backends at runtime, which the move to
bytecode emitted straight from the shader generators leaves no compiler
for. The frontend's own shader pipeline covers post-processing.
The presentation pass keeps a plain copy and the built-in correction
shader for output resampling, colour space and gamma correction and HDR
scaling, now compiled in rather than loaded from Sys/Shaders. The
graphics-mod system keeps its draw, EFB, projection and texture actions;
custom pipelines, materials, shader, mesh and sampler assets, the custom
constant buffers in every backend and the two mods built on them are
gone, along with the shader generators' custom-shader hooks.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.