Fanfiction, also known as fan fiction and fanfic, is fiction written by fans of a particular TV series, movie or book. It has probably been around as long as fiction has existed--girls penning their own ending to Little Women in which Beth survives and Jo marries Laurie, for instance. But it only emerged as a shared experience in the sixties, with the advent of serial TV shows that gained cult followings.

Fanfiction is most often associated with Star Trek, and indeed, it was at early Star Trek gatherings that fanfiction began to be shared with other fans. Originally it took the form of poorly mimeographed, hand-stapled fanzines (or just zines), but now fanfiction comes in slick illustrated products produced by modern desktop publishing tools.

The Internet brought new growth to fanfiction, with fans discovering each other worldwide, forming groups, mailing lists and newsgroups for the sharing of fan-written fiction and fan-painted art. Virtually every television series of interest to a young audience has a fanfic community associated with it. Books that gain cult followings, such as the Harry Potter series, are also known for their fanfic following of amateur authors.

Technically, fanfiction is a violation of the author or production company's copyright, where one exists. In general, copyright holders, such as authors or production companies, feign ignorance at the burgeoning community of writers producing fiction in the universe they 'own'. As long as fan fiction is shared freely, rather than sold for a profit, JK Rowling and others like her seem satified to look the other way. This is likely both an appreciation of the fact that fanfiction is a powerful form of free publicity that entices mass interest in a show, and a recognition of the negative publicity that could result from a corporation legally attacking the most dedicated members of its own fanbase. The Star Trek franchise has gone so far as to advertise short-story contests on their fanfic newsgroup, and has occasionally published fan-written fiction in their anthologies.

On the other hand, it is legal to use characters or places first described in works of fiction that are no longer protected by copyright, though these are often not considered fanfiction. Characters such as the Wicked Witch of the West from The Wizard of Oz, Huckleberry Finn, and Romeo and Juliet have all moved into the public domain, and it's therefore completely permissible for a new author to profit from their use. Interestingly, many new works that use these old characters have proven very successful. Likely, this is because many fans enjoy seeing familiar characters reworked into new stories, or viewed from a new perspective.

Novelists whose works are appropriated by fans are much more likely to pursue the matter; Anne McCaffrey, for instance, has gone to considerable lengths to keep her Dragonriders of Pern series free of fanfiction.

One of the most prevalent forms of fanfiction, and the most startling to those new to the concept, is erotic fiction. Viewers who felt that Muldar and Scully of X-Files should have had sexual relations, often expressed that point of view via a piece of erotic fiction. Erotic fanfic allows the authors and readers to experience a show or book in ways traditional media would never permit.

Along these same lines is erotic fanfiction known as slash. The name comes not from the amount of blood spilled, as in 'slasher movies', but from the "forward slash" keyboard character. Slash fanfiction posits a homoerotic relationship between two male characters, who were not thus related in the series, or whose relationship is implied via subtext so subtle as to be visible only to the most observant--or imaginative--viewer. The forward slash is used to separate the names of the two characters. The original slash relationship was Kirk/Spock (also K/S) from the original Star Trek series, but any series or movie with two or more attractive male leads is likely to have slash fanfiction written about them. Contrary to what one might expect, slash fanfic is believed written and read almost exclusively by women.

Slash purists don't consider female/female stories to be slash. This is a recurring topic of debate in the slash community. Also debatable--is it slash if the male/male relationship is canonical, as in shows such as Queer as Folk? Some say no.

Not everyone enjoys fanfiction. Some fans do not like seeing characters that have become dear to them interpreted by others, behaving in ways that may not be in keeping with their own concepts of those characters--whether the fanfiction is erotic or not. Other fans enjoy reading alternate stories, and find fanfiction an entertaining pastime, and a new way to indulge their interest in characters that have become important to them.

Fanfiction exists for almost any television series, popular movie or book. Authors are as often unskilled as skilled, so quality varies widely from very bad to very good. If the concept sounds enjoyable, a search engine will find most archives. If you find certain fanfiction disagreeable, pervading wisdom in the world of fanfic is to follow the example of the networks and ignore it.

Note: Fanfiction of protected material is a legal violation of copyright. Fans that choose to write fanfiction do so at their own risk.