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 in the Marvel Cinematic Universe leading up to "Age of Ultron". He rewrote some dialogue for "", directed the mid-credits scene of "", and suggested that James Gunn make "Guardians of the Galaxy" "weirder" after reading an early draft. Whedon said it was unlikely that he would return to make another sequel, stating that he "couldn't imagine doing this again". He remarked that not having created his own fictional universe in over five years felt wrong and intended to use the proceeds made from "Avengers: Age of Ultron" for such ventures. In January 2016, Whedon announced that he will no