Fallout RPG

I was barely aware but Modiphius a few years ago published a
 Fallout RPG. I only really became aware of it right now as the
 new TV show seems to have caused them to sell out of all the
 print books for the game.
They do still have the pdfs and even a free quickstart online though

https://www.modiphius.net/collections/fallout-the-roleplaying-game/products/fallout-the-roleplaying-game-quickstart-guide-pdf-free

https://www.modiphius.net/pages/fallout-the-roleplaying-game

I do actually think I remember at least one rather extensive
 fanmade system based on only the first two games and Fallout
 Tactics, but I doubt I could find this anymore.