Richard Linklater's long awaited "Boyhood" will premiere at the upcoming Sundance Film Festival, where it will screen on Sunday night. It's a welcome surprise addition to the Sundance schedule. In fact, we just listed "Boyhood" as one of the 50 Films Indiewire Wants to See in 2014.

For years known only as "Linklater's 12 Year Project," the nearly completed "Boyhood" is said to have begun production in Houston in the summer of 2002 and reportedly completed shooting in late 2013. Filmed over short periods from 2002 to 2013, "Boyhood" is a groundbreaking cinematic experience covering 12 years in the life of a family involving a divorced couple (Ethan Hawke and Patricia Arquette). At the center is their son Mason (Ellar Coltrane), who with his sister Samantha (Lorelei Linklater), are taken on an emotional and transcendent journey through the years, from childhood to adulthood. The experimental production has largely been shrouded in secrecy as Linklater has returned to it each summer.

With the addition of "Boyhood," the 2014 Sundance Film Festival in Utah, which kicks off on Thursday, will present 121 feature-length films, including 35 in competition.