The update to the tomshardware article lists this stuff.
Intel ME Bringup guides + (flash) tooling + samples for various platforms
Kabylake (Purley Platform) BIOS Reference Code and Sample Code + Initialization code (some of it as exported git repos with full history)
Intel CEFDK (Consumer Electronics Firmware Development Kit (Bootloader stuff)) SOURCES
Silicon / FSP source code packages for various platforms
Various Intel Development and Debugging Tools
Simics Simulation for Rocket Lake S and potentially other platforms
Various roadmaps and other documents
Binaries for Camera drivers Intel made for SpaceX
Schematics, Docs, Tools + Firmware for the unreleased Tiger Lake platform
(very horrible) Kabylake FDK training videos
Intel Trace Hub + decoder files for various Intel ME versions
Elkhart Lake Silicon Reference and Platform Sample CodePost too long. Click here to view the full text.