"This repository contains multiple implementations of the same 3D scene, using different APIs and frameworks on various platforms. The goal is to provide a comparison between multiple rendering methods. This is inherently biased due to the variety of algorithms used and available CPU/GPU configurations, but can hopefully still provide interesting insights on 3D rendering."

It's a mixed bag of APIs, software, hardware and tools, approaching the rendering in very different ways. There's even an offline renderer (Blender Cycles) and a software real time renderer in the repo.