FanFiction.Net

FanFiction.Net (often abbreviated as FF.net or FFN) is an automated fan fiction archive site. It was founded on October 15, 1998 by Los Angeles computer programmer Xing Li, who also runs the site. It has over 12 million registered users and hosts stories in over 40 languages.
The site is split into nine main categories: Anime/Manga, Books, Cartoons, Miscellaneous, Games, Comics, Movies, Plays/Musicals, and TV Shows. The site also includes the Crossover category, added on March 27, 2009. Users who complete the free registration process can submit their fan fiction, maintain a user profile, review other stories, apply for a beta reader position, contact each other via private messages, and maintain a list of favorite stories and authors. There are centralized communities and forums. In lieu of signing up with a new account, the website allows users to use their Google, Facebook, or Twitter accounts. The site also owns a Twitter account called FictionPress where users of the website are updated on changes and improvements made.
Creation.
In 1998, Xing Li, a software designer, created FanFiction.Net. The site was created as a repository for fan-created stories that revolved around characters from popular literature, television, comics, or real-world celebrities. Unlike other fan fiction sites, FanFiction.Net allowed stories about any characters rather than revolving around a specific set of characters, such as those from "Naruto", "Twilight", or "Kingdom Hearts". Registration was open to all people who claimed to be over 18, and by 2002 over 118,000 people were registered. (The age limit has since been moved down to 13.) At that time, one-third of the registrants self-identified as 18 or younger, and 80% were female.
Site content.
Writers may upload their stories to the site and assign them a category and rating (such as K, K+, T, and M). The ratings are no longer done on the MPAA system, due to cease-and-desist demands from the Motion Picture Association of America in 2005. A list of explanations for the rating system currently employed is available from the drop-down rating menu in each of the individual archives on the site. The MA (18+) rating is not permitted on this site. The site does not pay money to people for posting content or charge money for posting on the website, and it uses advertisements to pay for costs.
FanFiction.Net does not operate a screening or editorial board. Many users leave reviews after reading stories, most of which are positive. While reviews can be left by those without accounts, it is an option for all writers on the site to moderate "anonymous reviews", made by those who are not signed into an account.
The stories are based on books, television series, films, and video games. Stories are about recent works and older works. By 2001, almost 100,000 stories were posted on the website. Steven Savage, a programmer who operated a column on FanFiction.Net, described it as "the adult version of when kids play at being TV characters" and that the content posted on the website serves as examples for "when people really care about something" A. S. Berman of "USA Today" said in 2001 that FanFiction.Net "reads like the 21st century successor to the poetry slams of the Beat Generation." In 2011, Ogi Ogas described the website as 'the world's most popular "erotic" site for women'.
FanFiction.Net uses the rating system from FictionRatings.com. This system contains the ratings of K, K+, T, M and MA. The MA rating and explicit violent and/or sexual themes are forbidden.
In October 2008, the site underwent a major redesign of its admin/user area. Changes to how users check hits and reviews, post chapters, etc. were made.
Most popular sections.
As of March 30, 2021, the top 20 fandoms (i.e., the fandoms with the most stories submitted) on FanFiction.Net are (the figures are rounded to nearest thousand):
Notable long fanfiction works.
FanFiction.net also hosts one of the longest works of fiction ever written. "The Subspace Emissary's Worlds Conquest", a "Super Smash Bros." fanfiction written by FanFiction.net user AuraChannelerChris, gained media attention for its length of over four million words at the time of notice, more than three times as long as "In Search of Lost Time" written by Marcel Proust, and is still being written. The longest fanfiction on the site is "The Loud House: Revamped", a crossover fanfiction of "The Loud House" which is over 9,500,000 words long .
Disallowed fanfiction.
Copyright and trademark issues.
FanFiction.Net instituted several policy changes as it grew in size and popularity. These policies frequently led to the deletion of fanfiction based on the copyrighted works of certain published authors or containing specifically targeted content.
Since the site's founding, several professional authors and producers have asked that stories based on their copyrighted or trademarked works be removed, including Anne Rice, P. N. Elrod, Archie Comics, Dennis L. McKiernan, Irene Radford, J.R. Ward, Laurell K. Hamilton, Nora Roberts/J.D. Robb, Raymond Feist, Robin Hobb, Robin McKinley, and Terry Goodkind.
In addition, stories based on real-life celebrities were disallowed around 2003. Fan fiction based on professional wrestling, however, is still allowed, being the number one fandom in the "Miscellaneous" category.
NC-17 ratings.
On September 12, 2002, FanFiction.Net banned and removed material that was rated NC-17. Prior to the new policy, the site would use a pop-up to prompt readers to say whether they were over 17 or not, but since then, the site has relied on its users to report stories that are inappropriately rated. Some NC-17 material was moved to Adult-FanFiction.org (previously AdultFanFiction.Net), a similar site which was created to serve the adults who write R and NC-17 rated fan fiction. However, many stories containing explicit material still exist and have yet to be removed.
Story titles and summaries must be rated K.
CYOA (Choose-Your-Own-Adventure)/Reader-Insertion fics.
These have been banned since 2005, and the site removed all material that had the potential of inserting the reader into a fanfiction. Under the heading of "Entries not allowed," Item #5 says: "Any form of interactive entry: choose your adventure, second person/you based, Q&As, etc." 
Songfics.
In 2005, FanFiction.Net banned songfics which contain copyrighted lyrics. Public domain lyrics (such as those to "Amazing Grace") or lyrics written by the author of the fanfiction are allowed, however.
Lists.
Until April 21, 2002, in addition to fiction stories based on existing characters, the site had a section devoted to lists, generally humor-related, for example "20 Ways to Dump Your Girlfriend".
Globalization.
At first, FanFiction.Net's server was accessible mainly only in the West; and worked poorly, if at all, in other parts of the world. In late 2006, announcements were made of special web links designed for Europe and Asia. These were supposed to give other areas of the world a significant boost in server speed on the website. In 2007, all three web links were combined under one worldwide link. In an announcement on the home page, it was stated that the site would go global that year.
Prior to the reorganizations of 2002, FanFiction.Net contained approximately 20% of English-language fanfiction.
According to Hitwise, as of August 2007 FanFiction.Net comprised 34.7% of all traffic directed to sites in the Entertainment, Books and Writing category. For the week ending August 25, 2007, the site was ranked 159 out of over in terms of hits.
FictionPress.com.
FanFiction.Net's sister site, FictionPress.com, contains over 1 million original stories, poems, and plays. The site has a similar format and rules to FanFiction.Net, except that no fan fiction is allowed. Currently, there are more poems than prose.