Frozenbyte the people behind the Trine series has just released their editor for the Trine Enhanced Editon and Trine 2. This is a good thing you’ll be probably seeing the community for Trine for much longer than before because of this release. I’m expecting some great things from the community.
Some examples of older games that have had active communities like this mod for Halo: Combat Evolved which is a complete conversion which changes just about everything in the game. Remember this while you’re watching this game is 11 years old.
Another great game which still has a active modding scene is Killing Floor it might not be as old as Halo: Combat Evolved, but it’s still quite an old game. The video below is an Aliens Mod for Killing Floor that was updated just 3 weeks ago.
Mod tools greatly lengthen the life of a game because the community can express their ideas on the games engine and that’s usually a good thing because like some mods they can become full fledged games. (Dota, Killing Floor, etc.)