Set on the streets of 1980s Edinburgh, Scotland, 1996’s ‘Trainspotting’ follows the trials and tribulations of a group of young heroin addicts. Based on the novel of the same name by Scottish writer Irvine Welsh and directed by Danny Boyle (‘Slumdog Millionaire,’ ‘127 Hours’), the film often takes a humorous tone despite its obviously dark subject matter. That delicate balance, plus the cast’s gripping performances and the excellent companion soundtrack, helped ‘Trainspotting’ become a huge critical success throughout Europe and the States.

Many of the key cast members became stars after its release, so it’s no surprise ‘Trainspotting’ was voted the best Scottish film of all time in a 2004 poll. Amid buzz about a sequel in the works, decided it was time to look back at the main actors and see what they’ve been up to since the mid-'90s.

Ewan McGregor, Mark "Rent Boy" Renton

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Then: McGregor's portrayal of junkie Mark "Rent Boy" Renton proved to be his breakthrough role, bringing him to the attention of high profile casting agents in Hollywood.

Now: The 42-year-old actor has become a household name through his work in films such as 'Black Hawk Down,' 'Big Fish' and 'Moulin Rouge!' McGregor also landed the part of Obi-Wan Kenobi in the 'Star Wars' prequel trilogy.

Ewen Bremner, Daniel "Spud" Murphy

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Then: Bremner played "Spud," the most loveable heroin fiend you've ever seen on film.

Now: Like his 'Trainspotting' co-star McGregor, Bremner appeared in 2001's 'Black Hawk Down.' The son of two art teachers, he's amassed a filmography that also includes parts in 'Pearl Harbor,' 'Match Point' and 'Snatch.'

Jonny Lee Miller, Simon "Sick Boy" Williamson

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Then: The London-born Miller played Simon "Sick Boy" Williamson and was suggested for the film by McGregor. Miller got his character's accent down by hanging out in bars in Glasgow.

Now: Miller was famously married to Angelina Jolie for a brief period in the mid-'90s. Now wedded to actress Michele Hicks, Miller has appeared in both feature films and on television. He can currently be seen playing Sherlock Holmes in CBS' hit show 'Elementary.'

Robert Carlyle, Francis "Franco" Begbie

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Then: The part of "Franco" was originally intended for former Doctor Who actor Christopher Eccleston.

Now: Since garnering rave reviews for his work in 'Trainspotting,' Carlyle has gone on to have a successful acting career, appearing in movies like 'The Full Monty' and 'The World Is Not Enough.'

Kevin McKidd, Tommy Mackenzie

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Then: Before playing Tommy Mackenzie in 'Trainspotting,' McKidd made his film debut in 'Small Faces,' a 1996 Scottish gangster flick.

Now: Besides Boyle, McKidd has gone on to work with other celebrated directors such as Mike Leigh and Ridley Scott. He won praise for his portrayal of Lucius Vorenus on the HBO series 'Rome,' and in 2012, he released 'The Speyside Sessions,' an album of Scottish folk music.

Kelly Macdonald, Diane Coulston

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Then: Boyle wanted an actress with no prior experience for the role of Diane. Macdonald learned about the part while working as a waitress at a bar in Glasgow when she saw a flyer advertising the casting session for ‘Trainspotting.’

Now: In addition to appearing on HBO's 'Boardwalk Empire,' Macdonald keeps a busy feature film schedule and has played parts in 'No Country for Old Men,' 'Finding Neverland,' and 'Harry Potter and the Deathly Hollows - Part 2,' among other movies. She is married with two children to Travis bassist Dougie Payne.

Peter Mullan, Swanney "Mother Superior"

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Then: Along with 'Trainspotting' cast mate McGregor, Mullan also appeared in Boyle's directorial debut, 1994's award-winning 'Shallow Grave.'

Now: A busy character actor, Mullan's recently scored Primetime Emmy and Critics' Choice Television Award nominations for his work in the 2013 Sundance Channel miniseries 'Top of the Lake.'

James Cosmo, Mr. Renton

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Then: The veteran actor played the long-suffering father of McGregor's "Rent Boy" character.

Now: Cosmo is a sort of hero on the geek circuit thanks to his appearances in films like 'Highlander' and 'The Chronicles of Narnia: The Lion, the Witch and the Wardrobe.' He recently portrayed Jeor Mormont on the HBO sword-and-sorcerer fest 'Game of Thrones.'

Shirley Henderson, Gail

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Then: Henderson was already an experienced television actress by the time she was cast as Gail, "Spud" Murphy's girlfriend.

Now: She's since appeared in two 'Harry Potter' films and played French princess Sophie-Philippine in Sofia Coppola's highly stylized 2006 film 'Marie Antoinette.' Earlier this year, Henderson co-starred with James McAvoy in 'Filth,' a film based on another Irvine Welsh novel.

Irvine Welsh, Mikey Forrester

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Then: Released in 1993, 'Trainspotting' was Welsh's first published novel. He made a cameo appearance as a drug dealer in the film version.

Now: Welsh has released both a sequel (2002's 'Porno') and a prequel (2012's 'Skagboys') to 'Trainspotting.' He's also released five additional novels and four short story collections, and he's worked as a director and playwright.