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 Cabin in the Woods" (2012). He wrote and directed the Marvel Cinematic Universe superhero films "The Avengers" (2012) and its sequel "" (2015), and also co-wrote the script for the DC Extended Universe superhero film "Justice League" (2017), for which he also served as director on reshoots. Born in New York City on June 23, 1964 as Joseph Hill Whedon, and being a third-generation TV writer, he is a son of Tom Whedon, a screenwriter for "Alice" in the 1970s and "The Golden Girls" in the 1980s, and a grandson of John Whedon, who worked on "The Donna Reed Show"