Offshoots and subcommunities
As a community devoted to discussion and exploration of new ideas, fandom has become an incubator for many groups that started out as special interests within fandom, some of which have partially separated into independent intentional communities not directly associated with science fiction. Among these groups are comic-book fandom, media fandom, the Society for Creative Anachronism, gaming, and furry fandom, sometimes referred to collectively as "fringe fandoms" with the implication that the original fandom centered on science-fiction texts (magazines and later books and fanzines) is the "true" or "core" fandom. Fandom also welcomes and shares interest with other groups including LGBT communities, libertarians, neo-pagans, and space activist groups like the L5 Society, among many others. Some groups exist almost entirely within fandom but are distinct and cohesive subcultures in their own rights, such as filkers, costumers, and convention runners (sometimes called "SMOFs").
Fandom encompasses subsets of fans that are principally interested in a single writer or subgenre, such as Tolkien fandom, and Star Trek fandom ("Trekkies"). Even short-lived television series may have dedicated followings, such as the fans of Joss Whedon's Firefly television series and movie Serenity, known as Browncoats.
Participation in science fiction fandom often overlaps with other similar interests, such as fantasy role-playing games, comic books and anime, and in the broadest sense fans of these activities are felt to be part of the greater community of SF fandom.
There are active SF fandoms around the world. Fandom in non-Anglophone countries is based partially on local literature and media, with cons and other elements resembling those of English-speaking fandom, but with distinguishing local features. For example, Finland's national gathering Finncon is funded by the government, while all conventions and fan activities in Japan are heavily influenced by anime and manga.