Science fiction fandom 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 ("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
Joss Whedon Andrew Chambliss). As a result of the success of "Buffy the Vampire Slayer", Whedon was allowed the opportunity to make his 1999 spin-off series, "Angel". David Greenwalt and Whedon collaborated on the pilot that was going to be developed for The WB Network. During the series' early expansion, efforts were made by the network to mitigate Whedon's original concept. "Corrupt", a precociously optioned second episode, was entirely abandoned due to the gloominess written into the script. The tone was consequently softened, establishing in the opening episodes Angel Investigations as an idealistic, shoestring operation. It follows Angel, who works as a