The Organization For Transformative Works (OTW) is a non-profit organization that advocates for the transformative and legitimate nature of fan labor activities, including fan fiction, fan vids, anime music videos, and real person fiction. It is an organization advocating for the legality of fan works, and its primary focus is protecting fan fiction, fan art, fan videos, and other transformative works from legal snafus and commercial exploitation.
The Organization for Transformative Works offers the following services to fans in fandoms:
An open-source, non-commercial, non-profit archive for fan fiction and other transformative fanac ("Archive of Our Own"), built by fans (many without previous coding experience)
The OTW has also submitted several amicus briefs to the courts in several cases involving intellectual property law:
In Fox vs. Dish, the OTW (in coalition with the Electronic Frontier Foundation and Public Knowledge) submitted an amicus brief which argued in defense of digital recording methods used by Dish Network, claiming that "The popular fanwork genre of noncommercial videos (“vids”) uses clips from television shows or film, reworking them in a way that comments on or critiques the original. The Copyright Office has held that substantial numbers of vids constitute fair uses. But the creation of fan vids requires intermediate digital copying and processing in order to produce the transformative final product. OTW thus believes that intermediate copying performed to facilitate fair use constitutes fair use." 
In the case of Ryan Hart vs. Electronic Arts, the OTW (in combination with the Digital Media Law Project and the International Documentary Association) submitted a brief arguing that Electronic Arts's use of factual information (such as the height, weight, and jersey number of football players) in creative works (in this case, video games) is protected by the First Amendment.
The OTW has also instituted several projects for preserving fan history and culture. One such project was the creation of Fanlore, a wiki for preserving fandom history. The Fanlore wiki was first revealed in beta in 2008, with a full release in December 2010.
The OTW also has several "Open Doors" projects dedicated to the preservation of fannish historical artifacts. These projects include The Fan Culture Preservation Project, a joint venture between the OTW and the Special Collections department at the University of Iowa to archive and preserve fanzines and other non-digital forms of fan culture, and The GeoCities Rescue Project, which attempted to preserve content originally hosted on Yahoo's GeoCities by transferring that content to new locations on the Archive of Our Own or within the Fanlore wiki. Other miscellaneous artifacts and collections are stored on the OTW's main servers in the Special Collections gallery.
Created by the OTW, the Archive of Our Own (AO3) is an open-source, non-commercial, non-profit archive for fan fiction and other transformative fanac. The Archive is built and run entirely by volunteers, many without previous coding experience . The Archive was publicly launched into Open Beta on 14 November 2009, and has been growing steadily since, passing 1 million fanworks in February, 2014.  The archive was named one of Time magazine's 50 Best Websites of 2013.