Independent animation is animated short cartoons and feature films produced outside the professional Hollywood animation industry. A good portion of the work is viewed in animation festivals and private screen rooms along with schools that produce animation through instruction. The significance of independent animation is as important as studio fare.
Early independent animation
The history of animation is as old as the film industry itself. Independent animators have produced innovative, often experimental, shorts since the silent era. One of the earliest feature-length animated films was The Adventures of Prince Achmed, made in 1926 by Lotte Reiniger, a German artist who made silhouette animation using intricate cut-out figures and back-lighting. She made another feature, Dr. Dolittle, in 1928.
1959 saw the first independent animated film to win an Oscar with John Hubley's Moonbird which was also produced by wife and collaborator Faith Hubley using limited animation to tell their own personal stories. 
The United States
Success of independent animation
In the late 1960s, animator Ralph Bakshi and producer Steve Krantz founded Bakshi Productions, establishing the studio as an alternative to mainstream animation by producing animation his own way and accelerating the advancement of female and minority animators. He also paid his employees a higher salary than any other studio at that time. In 1969, Ralph's Spot was founded as a division of Bakshi Productions to produce commercials for Coca-Cola and Max, the 2000-Year-Old Mouse, a series of educational shorts paid for by Encyclopædia Britannica. However, Bakshi was uninterested in the kind of animation he was producing, and wanted to produce something personal. Bakshi soon developed Heavy Traffic, a tale of inner-city street life. However, Krantz told Bakshi that studio executives would be unwilling to fund the film because of its content and Bakshi's lack of film experience. While browsing the East Side Book Store on St. Mark's Place, Bakshi came across a copy of R. Crumb's Fritz the Cat. Impressed by Crumb's sharp satire, Bakshi purchased the book and suggested to Krantz that it would work as a film.
Fritz the Cat was the first animated film to receive an X rating from the MPAA, and the highest grossing independent animated film of all time. Bakshi then simultaneously directed a number of animated films, starting with Heavy Traffic. Ralph Bakshi became the first person in the animation industry since Walt Disney to have two financially successful films released back-to-back.
Other independent animators during this time included Charles Braverman,  Gene Deitch,  Marv Newland, Fred Wolf and Will Vinton. The latter two would go on to win Academy Awards for Best Animated Short Film alongside with the works of the Hubleys and Ernest Pintoff starting in the late 50's-early 60's.
Other animators like Jeff Scher , Joanna Priestley, Kathy Rose, Robert Swarthe, Vince Collins, Barrie Nelson, Eli Noyes, Sky David (aka Dennis Pies), Steve Segal, Adam Beckett and George Griffin also made experimental animation during the mid- to late 1970s through the early- to mid-1980s. 
In the 1970s, independent animators like Sally Cruikshank continued to explore independent and D.I.Y. distribution options, but were still largely met with rejection even though their work is now considered ground breaking.
Collections of independent films have been gathered for theatrical viewing, and video release, under such titles as the International Tournee of Animation (which existed between about 1966 and the late 1990s), Spike and Mike's Classic Festival of Animation (1977 to 1990) and Spike and Mike's Sick and Twisted Festival of Animation since 1990. Contemporary independent animators, including Steven Subotnick, Paul Fierlinger, Bill Plympton, Don Hertzfeldt, Nina Paley, Suzan Pitt and PES have also made work outside of the studio system.
Later independent animation
The rise of the Internet in the 1990s and 2000s saw an exponential increase in the production of independent animation which included personal independent works by Timothy Hittle,  Lewis Klahr  and John Schnall.  Personal computer power increased to the point where it was possible for a single person to produce an animated cartoon on a home computer, using software such as Flash, and distribute these short films over the World Wide Web. Independently produced Internet cartoons flourished as the popularity of the Web grew, and a number of strange, often hilarious short cartoons were produced for the Web.
In the late 1990s, an independent animated short film called The Spirit of Christmas was produced for under $2,000 by two artists, Matt Stone and Trey Parker. This film was widely distributed on the Internet as a pirated cartoon, and its phenomenal popularity gave rise to the popular television animated series South Park. Limited 1990s bandwidth made streaming difficult, if not impossible. While some animators like Spümcø's John K. opted to use Flash, it still required a plug-in making it unviewable in many early web browsers. Other early online animators like M. Wartella opted to use the Animated GIF to overcome these limitations and create early web-based animation viewable through all browsers.
Continued success for independent animation occurred in the 2000s with animated shorts such as Making Fiends. Both shorts garnered enough support to be turned into full-length TV Series, airing on Nicktoons Network and Big TV, respectively.
By the late mid-2000s, YouTube and the Internet and like-minded online video distribution, in addition to independent broadcasting sites that followed, proved to be a dominant form of independently distributed, broadcast, edited, and produced animation TV shows, anime, feature films, music videos, retro animation, commercials, trailers, original online animation content, and web exclusives (which would otherwise not stand a chance of seeing airtime on more normal, seemingly infinitely more expensive forms of mainstream broadcasting on traditional television networks, which still continue to function on a more conservative and old fashioned distribution matrix). The Annoying Orange, which started off as a series of viral quasi-CGI animated comedy shorts on YouTube, quickly gained a cult following and an excess of 100 million views online. It is an example of an animated web-series to transition between Internet and television distribution successfully, as an animated series on Cartoon Network.
Independent animation outside the United States
The National Film Board of Canada began production of animation when Norman McLaren joined the organization in 1941. The NFB proved to be an organization that would give Canada a presence in the film world. The animation department eventually gained distinction, particularly with the pioneering work of McLaren, an internationally recognized experimental filmmaker. The NFB was a pioneer in several novel techniques such as pinscreen animation, but most of the Oscars and many other awards it won were done in traditional cel animation (with the exceptions of The Sand Castle and Ryan).
McLaren's Oscar-winning Neighbours popularized the form of character movement referred to as pixillation, a variant of stop motion. The term pixilation itself was created by NFB animator Grant Munro in an experimental film of the same name.
The United Kingdom
The BFI funded around thirty pieces of experimental animation between the mid-fifties to mid-nineties (notable examples: The Quay Brothers). Another major contributor to independent animation in Britain was Channel 4, which gained an international reputation as one of the most adventurous broadcasters of animation featuring works from Joanna Quinn (Girls' Night Out), Paul Barry (The Sandman), Mark Baker (The Village) and former NFB animator Paul Driessen (3 Misses). 
- Zagreb Film
- Pannonia Film Studio
- United Productions of America
- Adult animation
- Animated documentary
- Halas & Batchelor
- Richard Williams-director of the independently produced The Thief and the Cobbler
- National Film Board of Canada
- Cartoon Saloon
- Animation Show of Shows-showcase for both independent and mainstream animated shorts
-  "Lotte Reiniger", William Moritz, Animation World Magazine, Issue 1.3
- "The Unnatural History of Independent Animated Films on 16mm". www.awn.com.
- "MoMA | An Auteurist History of Film: Independent Animation, 1947–60". www.moma.org.
- "Film Notes -Independent Short Films". www.albany.edu.
- Gibson, Jon M.; McDonnell, Chris (2008). "First Gigs". Unfiltered: The Complete Ralph Bakshi. Universe Publishing. p. 54. ISBN 0-7893-1684-6.
- Sito, Tom (2006). "Suits". Drawing the Line: The Untold Story of the Animation Unions from Bosko to Bart Simpson. University Press of Kentucky. p. 50. ISBN 0-8131-2407-7.
- Television/radio Age. Television Editorial Corp. 1969. p. 13.
- Gibson, Jon M.; McDonnell, Chris (2008). "Fritz the Cat". Unfiltered: The Complete Ralph Bakshi. Universe Publishing. pp. 58, 62–63, 80–81. ISBN 0-7893-1684-6.
- Solomon, Charles (1989). Enchanted Drawings: The History of Animation. New York City: Alfred A. Knopf. p. 275. ISBN 0-394-54684-9.
- Mira, Dev (13 June 2019). "How to Save GIFS from Twitter". Techolac - Computer Technology News. Retrieved 15 July 2019.
- "The Creativity of Pre-Digital Animation in the 1970s and '80s". Hyperallergic. February 2, 2018.
- Landekic, Writer Lola; Landekic, Interviewer Lola; Perkins, Editor Will; Published May 20, 2015. "Sally Cruikshank: A Career Retrospective, Part 1". www.artofthetitle.com.CS1 maint: Extra text: authors list (link)
- "A Rare Treat: Bay Area Animation". KQED. August 23, 2011.
- "Re-Animation: An Evening with Lewis Klahr". Redcat. September 2, 2009.
- "Death Laughs Among Us: The Films of John Schnall". Animation World Network.
- UTC, Brenna Ehrlich2011-04-15 18:03:34. "Popular YouTube Series Annoying Orange Moves to TV". Mashable. Retrieved 2016-01-02.
- "Animator Pursues a Minimal Approach to His Art". archive.nytimes.com.
- "The BFI and Animation - Screenonline". Retrieved 2011-04-30.
- "Channel 4 and Animation - Screenonline". Retrieved 2011-04-30.
- "With Channel 4 Television Corporation (Sorted by Popularity Ascending)". IMDb.