Most F/LOSS projects would qualify: quite a lot of unix distributions are old, active, big; gnu packages too; programming languages. Maybe you meant kind of soc

Most F/LOSS projects would qualify: quite a lot of unix distributions are old, active, big; gnu packages too; programming languages. Maybe you meant kind of social platforms and not just software, but imho they are just like wikipedia since usually a free software project encompasses some mailing lists, wiki, collaboration.. More wikipedia-like: musicbrainz.