Way back in 2003, I began developing a d20 compatible universe based on my own original writings from 1983 up to what was then the present day (2003). Essentially it was a comicbook style universe where pulp heroes like the Shadow and Doc Savage coexisted with iconic character types from later decades.
In essence it was similar to the Wold-Newton Universe, only without the same tiresomely repetitive attempts to make EVERYONE related- I allowed for several bloodlines at least.
I also wanted to cater to the darkening of the light that comics experienced and continue to experience.
Thus there came the RPG books GOLDEN, ETERNIUM, ZOMBIENOMICON and ZOMBIENOMICON II: GORDIAN WORLD. There were other tie-in books too- A Vintage From Atlantis was the first d20 piracy rulebook and sourcebook standalone, Monkey On Your Back catered to my personal taste for Planet of the Apes type adventures, and Red Drums was a very dark parallel world universe where the 1980s had Gerry Anderson style technology- and Martian animated zombies.
All in all it was quite successful, particularly judged from the standards of the amount of my material which was plagiarised- always the sincerest form of imitation.
Be that as it may, the lines were always there ready to be followed back into actual comicbook publishing and despite a few abortive starts that is what is finally occurring now. Of course the universes being published are very different again- but that's probably a good thing. :)
If we still have copies anywhere I will put up the timelines etc. from the game books.