I grew up playing DOOM, but if I were to boot up the original game I would find it frustrating to play by modern standards (e.g. mouse movement?!). Thankfully, there are a ton of source ports that modernize the engine and make the game more accessible to current gaming sensibilities (e.g. WASD-movement). They're basically community remasters of the game.

It got me wondering about what other games have strongly benefited from tools that exist outside of the game itself.

Examples of what I mean:

1. Source ports (e.g. DOOM)
2. Community bugfixes (e.g. Vampire: The Masquerade - Bloodlines)
3. Restored/extended content (e.g. Star Wars: Knights of the Old Republic II)
4. Significant mods (e.g. Frostfall for Skyrim)
5. Rulesets/challenges (e.g. Nuzlocke Challenge for Pokémon)
6. Anything else that doesn't fit the above categories