GPUs & Drivers (Devices, IoT & Hardware): open-source projects that exist because someone reverse engineered a closed product, sorted by GitHub stars.
Vulkan reimplementation of NVIDIA DLSS 5 neural rendering network, bit-exact against original
Reverse-engineered documentation of the Broadcom VideoCore IV
Tools and docs for reverse engineering NVIDIA GPUs (nouveau)
Reverse-engineering tools and docs for Qualcomm Adreno GPUs
Reverse engineering of Vivante GPU driver and tools
Userspace MediaTek mt76 USB Wi-Fi driver for macOS monitor-mode sniffing