Lost is an American serial drama television series that follows the lives of plane crash survivors on a mysterious tropical island, after a passenger jet flying between Australia and the United states crashes somewhere in the South Pacific. Each episode typically features a primary storyline on the island as well as a secondary storyline from another point in a character's life. The show was created by Demon Lindelof, J. J. Abrams and Jeffrey Lieber, and is filmed primarily on location in Oahu, Hawaii. The pilot episode was first broadcast on September 22, 2004, Since then, three seasons have aired. The show is produced by ABC Studios, Bad Robot Productions and Grass Skirt Productions and airs on the ABC Network in the United States. Its incidental music is composed by Michael Giacchino. The current executive producers are Abrams, Lindelof, Carlton Cuse, Jack Bender, Jeff Pinkner and Bryan Burk. Because of its large ensemble cast and the cost of filming in Hawaii, the series is one of the most expensive on television.

A critical and popular success, Lost garnered an average of 16 million viewers per episode on ABC during its first year, and won numerous industry awards including the Emmy Award for Outstanding Drama Series in 2005, Best American Import at the British Academy Television Awards, also in 2005, and the Golden Globe for Best Drama in 2006.

Reflecting its devoted fan base, the show has become a staple of American popular culture with references to the story and its elements appearing in other television shows, commercials, comic books, webcomics, humor magazines and song lyrics. The show's fictional universe has also been explored through tie-in novels, board and video games, and an alternative reality game, The Lost Experience.

In May 2007 it was announced that Lost will continue for its fourth, fifth, and sixth seasons, concluding with the 117th produced episode in May 2010. These three final seasons will consist of 16 episodes each, running weekly in the spring uninterrupted by repeats.

The series began development in January 2004, when Lloyd Braun, head of ABC at the time, ordered an initial script based on his concept of a cross between the movie Cast Away and the popular reality show Survivor. Jeffrey Lieber was hired, based on his pitch to write the pilot. Unhappy with the result and a subsequent re-write, Braun contacted J. J. Abrams, creator of the TV series Alias, to write a new pilot script. Although initially hesitant, Abrams warmed up to it on the condition that the show have a supernatural angle to it, and collaborated with Damon Lindelof to create the series' style and characters. The development of the show was constrained by tight deadlines, as it had been commissioned late in the 2004 season's development cycle. Despite the short schedule, the creative team remained flexible enough to modify or create characters to fit actors they wished to cast.

Lost's two-part pilot episode was the most expensive in the network's history, reportedly costing between US $10 and US $14 million, compared to the average cost of an hour-long pilot in 2005 of US $4 million. The show, which debuted on September 22, 2004, became one of the biggest critical and commercial successes of the 2004 television season. Along with fellow new series Desperate Housewives and Grey's Anatomy, Lost helped to reverse the flagging fortunes of ABC. Yet, before it had even aired, Lloyd Braun was fired by executives at ABC's parent company, Disney, because he had greenlighted such an expensive and risky project.

The world premiere of the pilot episode was on July 24, 2004 at Comic-Con International in San Diego.

Episodes have a distinct structure: following a recap of events relevant to the upcoming narrative, each show begins with a cold open. Often a close up of a character's eye will follow. At a dramatic juncture, the screen cuts to black and the title graphic, slightly out-of-focus, glides towards the viewer accompanied by an ominous, discordant sound. The opening credits generally appear alphabetically by last name over the scenes that immediately follow. Guest stars are credited in order of importance, with those appearing on the island credited before those who appear in flashbacks. While there is a continuous story arc, each episode relates events concurrently with off-island flashbacks and later, flashforwards, centered on a particular character. The majority of episodes end with a suspenseful twist or cliffhanger, revealed just seconds before a smash cut to black and the title graphic. Others, following a plot resolution, will finish with a reflective closing scene that precedes a simple fade to black, and in particularly tragic or heart-felt closing scenes, the booming noise that accompanies the title graphic will be silenced, amplifying the impact of the event.

Lost features incidental music performed by the Hollywood Studio Symphony Orchestra and composed by Michael Giacchino, whose score is primarily orchestral, incorporating several recurring themes for events and characters. Giacchino achieved some of the sounds for the score using unusual instruments, such as striking suspended pieces of the plane's fuselage.
The opening theme played as the fuzzy out of focus, off-axis Lost logo spins into view is taken from the preset "Armenian Sun" on the Spectrasonics Atmosphere software synthesizer.
On March 21, 2006, the record label Varèse Sarabande released the original television soundtrack for Lost's first season. The soundtrack included select full-length versions of the most popular themes of the season and the main title, which was composed by series creator J.J. Abrams. Varèse Sarabande released a soundtrack featuring music from the second season of Lost on October 3, 2006.
Pop culture songs have been used sparingly in the series, given the mainly orchestral score. When such songs are featured, they usually originate from a diegetic source, meaning that they are usually generated by an action of one of the characters. Examples are the various songs played on Hurley's portable CD player throughout the first season (until it finally broke in ...In Translation) or the use of the record player in the second season, which included Cass Elliot's "Make Your Own Kind of Music" in the second season premiere and Petula Clark's "Downtown" in the third season premiere. In two episodes, Charlie is shown on a street corner playing guitar and singing the Oasis song "Wonderwall". In the third season's finale, Jack is driving down the street listening to Nirvana's "Scentless Apprentice," right before he arrives to the Hoffs/Drawlar Funeral Parlor. The only pop song that has ever been used without a source is Ann-Margret's "Slowly," in the episode I Do.
In some international broadcasts, alternate music is utilized. For instance, in the Japanese broadcast of Lost, Season 1's theme song is "Here I Am" by Chemistry and Season 2's theme song is "Losin'" by Yuna Ito.

Lost is filmed in 35 mm, on Panavision cameras, almost entirely on the Hawaiian island of Oahu. The original island scenes for the pilot were filmed at Mokul%u0113%u02BBia Beach, near the northwest tip of the island. Later beach scenes take place in secluded spots of the famous North Shore. Cave scenes in the first season were filmed on a sound stage built at a Xerox parts warehouse, which had been empty since an employee mass shooting took place there in 1999. The sound-stage and production offices have since moved to the Hawaii Film Office-operated Hawaii Film Studio, where the sets depicting Season 2's "Swan Station" and Season 3's "Hydra Station" interiors were built. Various urban areas in and around Honolulu are used as stand-ins for locations around the world, including Los Angeles, New York, Iowa, Miami, South Korea, Iraq, Nigeria, England, France and Australia. For example, scenes set in a Sydney airport were filmed at the Hawaii Convention Center, while a World War II-era bunker was used as an Iraqi Republican Guard installation. Extensive archives of filming locations are tracked at a repository at Lostvirtualtour.com

In addition to traditional terrestrial and satellite broadcasting, Lost has been at the forefront of new television distribution methods. It was one of the first series issued through Apple's iTunes Store service for playback on an iPod or within the iTunes software. Since October 2005, new episodes, without commercials, have been available for download the day after they air on ABC, to American audiences only (restriction based on credit card billing address).

In April 2006, Disney announced that Lost would be available for free online in streaming format, with advertising, on ABC's website, as part of a two-month experiment of future distribution strategies. The trial, which ran from May to June 2006, caused a stir among network affiliates who were afraid of being cut out of advertising revenue. The streaming of Lost episodes direct from ABC's website was only available to viewers in the United States due to international licensing agreements.

The UK's Channel 4 has also allowed access to the series online. Both parts of "Pilot" were available to watch for free, and other episodes cost GB£0.99 each. Season two installments are made available two weeks after their Channel 4 debut, and the episodes expire after several months. Due to licensing agreements, the service is only accessible in the UK. Channel 4 have now teamed up with Virgin Media's On Demand function, allowing viewers to watch episodes from Season One and Season Two at any time in HD. A 24-hour rental costs £0.99 per episode. They are also available in Standard Definition as part of a subscription to the TV Choice on Demand Service.

As of third quarter, 2006, France's TF1 has allowed online access to the French version of Season Two; episodes cost %u20AC1.99. Each episode is issued online just after being broadcast.

Since August 6, 2007, Virgin Media started to show every previously aired episode on its Virgin Central portal, available to all Virgin Media TV subscribers. The first three episodes were made available on this date.

On the August 29, 2007, Lost became available for download from the iTunes Stores in the United Kingdom. Unlike the Channel 4 episode downloads, these downloads do not expire.

Lost: The Complete First Season was released as a widescreen seven-disc Region 1 DVD box set in the USA on September 6, 2005, two weeks before the premiere of the second season. It was distributed by Buena Vista Home Entertainment.

In addition to all the episodes that had aired, it included several DVD extras such as episode commentaries, behind-the-scenes footage and making-of features as well as deleted scenes, deleted flashback scenarios and a blooper reel.

The same set was released on November 30, 2005 in Region 4, and on January 16, 2006 in Region 2. The latter was titled Lost: The Complete First Series. As has become standard for Region 2, the series was first released split into two parts: the first twelve episodes of series 1 were available as a widescreen four-disc Region 2 DVD box set on October 31, 2005, while the remaining thirteen episodes of series 1 were released on January 16, 2006. The DVD features available on the Region 1 release were likewise split over the two box sets.

The second season was released as a widescreen seven-disc Region 1 DVD box set in the USA on September 5, 2006 and on Region 2 DVD on October 2, 2006, retitled as Lost: The Complete Second Series. Each of these releases also contained DVD extras, including Behind the Scenes Footage, deleted scenes and a "Lost Connections" chart, which shows how all of the characters on the island are inter-connected with each other.

Again, the series was initially delivered in two sets for Region 2: the first twelve episodes were released as a widescreen four-disc DVD box set on July 17, 2006. The remaining episodes of series 2 were released as a four-disc DVD box set on October 2, 2006. The set was released in Region 4 on October 4, 2006.

Both Seasons 1 and 2 of Lost have sold successfully on DVD. The Season 1 boxset entered the DVD sales chart at number two in September 2005, and the Season 2 boxset entered the DVD sales chart at the number one position in its first week of release in September 2006, believed to be the second TV-DVD ever to enter the chart at the top spot. First day DVD sales for Lost Season 2 are thought to have been as high as 500,000 copies sold.

The third season is due to be released in region 1 on December 11, 2007. Season 3 was released for sale and rental in Brazil (region 4) on September 26, 2007. The local release appears to be the same one slated to go into general sale in region 1 on December 11, 2007. The Brazilian seven-disc box set contains all 23 episodes screened in the third season (21 episodes and a two-parter season finale entitled "Through The Looking Glass"). Total episode running time is approximately 989 minutes. All episodes are widescreen. Besides featuring the original 5.1 Dolby Digital track in English, episodes also come with a choice of both Portuguese and Spanish tracks in 2.0 Dolby Surround. Subtitles and menus are available in English, Portuguese, Spanish, Chinese (Simplified), Korean, Thai, Malaysian, and Bahasa Indonesian. Some of the episodes (eg. Exposé) offer an audio commentary track option, as was the case with some episodes of previously released seasons. Disc 7 is entirely bonus material (approx. 169 minutes), and includes the following features: The Lost Book Club, Lost Flashbacks, Lost on Locations, The World of the Others, Lost in One Day, Crew Tribute With Evangeline Lilly, Deleted/Unreleased Scenes, and a Blooper Reel. The box set is available for sale everywhere in Brazil and over the web on major Brazilian online stores. The average going-on price for the box set is R$154 (approx. USD $80). In the UK it is due to be released on October 22, 2007. In New Zealand it is due to be released on October 22. In Australia, it is due to be released on October 17. 2007. A Blu-ray release for the third season DVDs was commissioned by Disney in July and will cost $124.99. As with seasons one and two, the third season release will include audio commentaries with the cast and crew, bonus featurettes, deleted scenes, and bloopers.

The opening season featured 14 regular speaking roles, making it the second largest cast in American primetime television behind Desperate Housewives. While a large cast makes Lost more expensive to produce, the writers benefit from more flexibility in story decisions. According to series executive producer Bryan Burk, "You can have more interactions between characters and create more diverse characters, more back stories, more love triangles."

The initial season had 14 major roles getting star billing. Naveen Andrews portrayed former Iraqi Republican Guard Sayid Jarrah. Emilie de Ravin played the pregnant Australian Claire Littleton. Matthew Fox acted as the troubled surgeon and protagonist Jack Shephard. Jorge Garcia portrayed Hugo "Hurley" Reyes, an unlucky lotto winner. Maggie Grace played Shannon Rutherford, a former dance teacher. Josh Holloway acted as con man James "Sawyer" Ford. Yunjin Kim played Sun-Hwa Kwon, the daughter of a powerful Korean businessman and mobster, with Daniel Dae Kim as her husband Jin-Soo Kwon. Evangeline Lilly portrayed fugitive Kate Austen. Dominic Monaghan acted as an ex-rock star drug addict Charlie Pace. Terry O'Quinn played the mysterious John Locke. Harold Perrineau portrayed construction worker Michael Dawson, while child actor Malcolm David Kelley acted as his young son, Walt Lloyd. Ian Somerhalder played Boone Carlyle, chief operating officer of his mother's wedding business and step brother of Shannon.

During the first two seasons, some characters were written out to make room for new characters with new stories. Boone Carlyle was the first major character to be written out in season one. Walt became a guest star after the events of the first season's finale, making rare appearances throughout season two. Shannon's departure eight episodes into season two made way for newcomers Mr. Eko, a Nigerian Catholic priest and former criminal played by Adewale Akinnuoye-Agbaje, Ana Lucia Cortez, an airport security guard and former police officer played by Michelle Rodriguez, and Libby, a purported clinical psychologist portrayed by Cynthia Watros. Ana Lucia and Libby were written out of the series toward the end of season two, as were Michael and Walt.

In season three, Henry Ian Cusick received star billing as former Scottish soldier Desmond David Hume, as did Michael Emerson in the role of Ben Linus (formerly known as Henry Gale), a high ranking member of the "Others." In addition, three new actors joined the regular cast: Elizabeth Mitchell, as Dr. Juliet Burke and Kiele Sanchez and Rodrigo Santoro as couple Nikki Fernandez and Paulo. Eko was written out early in the season; Nikki and Paulo were killed mid-season in their first flashback episode. Finally, Charlie Pace was written off in the season finale.

In season four, Harold Perrineau rejoins the main cast to reprise the role of Michael Dawson. Along with Perrineau, Malcolm David Kelley will also reprise his role as Walt in unknown extent. Fisher Stevens joins the cast in the recurring role of Minkowski. An additional five new actors have joined the cast. Ken Leung, Lance Reddick, Rebecca Mader, Jeremy Davies and Jeff Fahey have all been cast in unknown, yet much speculated roles. The actors are expected to have recurring roles throughout the season.

Numerous supporting characters have been given expansive and recurring appearances in the progressive storyline. In the second season, Rose Henderson played by L. Scott Caldwell and tail section survivor Bernard Nadler played by Sam Anderson were featured in a flashback episode after being reunited. Mira Furlan as Danielle Rousseau, the shipwrecked Frenchwoman, appears throughout the series. Some of the "Others," including M. C. Gainey as Tom, William Mapother as Ethan Rom, Tania Raymonde as Alex Rousseau and Nestor Carbonell as Richard Alpert, have been shown in both flashbacks and the ongoing story. Similarly, Jack's father Christian Shephard (John Terry) has appeared in multiple flashbacks of various characters.

On May 7, 2007, ABC Entertainment President Stephen McPherson announced that Lost will end during the 2009-2010 season with a "highly anticipated and shocking finale." "We felt that this was the only way to give [Lost] a proper creative conclusion," McPherson said. Beginning with the 2007-2008 television season, the final 48 episodes of Lost will be aired as three seasons with sixteen episodes each. Thus, Lost will conclude with its sixth season. These seasons are to be aired uninterrupted in the first half of those years.

The announcement by ABC was called "bold and unprecedented" by Lost's executive producers Damon Lindelof and Carlton Cuse. Lindelof and Cuse also stated that they "always envisioned Lost as a show with a beginning, middle, and end," and that by announcing when the show would end that viewers would "have the security of knowing that the story will play out as we've intended." Co-creator J.J. Abrams also praised the decision, remarking, "It is the right choice for the series and its viewers. It takes real foresight and guts to make a call like this. I applaud ABC and Touchstone for making this happen."

In the meantime, Sci Fi Channel and G4 have purchased the rights to broadcast reruns of Lost beginning Fall 2008.

Capping its successful first season, Lost won the Emmy Award for Outstanding Drama Series and J. J. Abrams was awarded an Emmy in September 2005 for his work as the director of Pilot. Terry O'Quinn and Naveen Andrews were nominated in the supporting actor category. Lost swept the guild awards in 2005, winning the Writers Guild of America Awards 2005 for outstanding achievement in writing for a dramatic television series, the 2005 Producers Guild Award for best production, the 2005 Director's Guild Award for best direction of a dramatic television program, and the Screen Actors Guild Awards 2005 for best ensemble cast. It has been nominated for a Golden Globe Award for best drama series every year it has been eligible, and won the award in 2006. In 2005, Matthew Fox and Naveen Andrews received Golden Globe nominations for Best Lead Actor and Best Supporting Actor in a Drama Series respectively, and in 2007, Evangeline Lilly received a nomination in the Best Lead Actress category. Lost did win the 2005 British Academy of Film and Television Award for Best American Import. In 2006, Jorge Garcia and Michelle Rodriguez took home ALMA Awards for best Supporting Actor and Actress, respectively, in a television series. It won the Saturn Award for Best Television Series in both 2005 and 2006. In, 2005 Terry O'Quinn won a Saturn Award for Best Supporting Actor in a television series, and in 2006, Matthew Fox won for Best Lead Actor. Lost won consecutive Television Critics Association Awards for Outstanding Achievement in Drama, for both its first and second seasons. Consecutively as well, it won in 2005 and 2006 the Visual Effects Society Award for Outstanding Supporting Visual Effects in a Broadcast Program. Malcolm David Kelley won a Young Artist Award for his performance as Walt in 2006. In 2005, Lost was voted Entertainment Weekly's Entertainer of the Year. The show won a 2005 Prism Award for Charlie's drug storyline in the episodes Pilot, House of the Rising Sun, and The Moth. Further, Lost was nominated for but did not win a Writer's Guild Award and Producer's Guild Award again in 2007. In June 2007, Lost beat out over 20 nominated television shows from countries all over the globe to win the Best Drama award at the Monte Carlo Television Festival. On September 16th of 2007, Terry O'Quinn won an Emmy for Best Supporting Actor in a Drama Series for his role as John Locke.