The new DOOM is a perfect addition to the franchise, using the new id Tech 6 engine where ex-Crytek Tiago Sousa now assumes the role of lead renderer programmer after John Carmack’s departure. Historically id Software is known for open-sourcing their engines after a few years, which often leads to nice remakes and breakdowns. Whether this will stand true with id Tech 6 remains to be seen but we don’t necessarily need the source code to appreciate the nice graphics techniques implemented in the engine.
fascinating how much work goes into this. see also the analysis of the 2020 successor, using id Tech 7.