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 "" also spanned three issues, and was written by Whedon and Brett Matthews. Whedon later co-wrote "The Shepherd's Tale" with his half brother Zack. As a guest director, he contributed two 2007 episodes of "The Office" ("Business School" and "Branch Wars") and a 2010 episode of "Glee" ("Dream On"). Denoting this period, Whedon has said, "I had free time, but I'm pretty sure I mean my career was on the skids". In collaboration with Fábio Moon, Whedon created the free webcomic titled "Sugarshock!", as part of the revival of "Dark Horse Presents", which was launched on Myspace. Whedon later executive