Big holiday shopping markets, including the free 77th Christ Church Cambridge Christmas Fair from 10 a.m. to 3 p.m. Saturday at Christ Church Cambridge, Zero Garden St., Harvard Square, with gifts, music and food, games and a raffle with grand prizes including apparel, snacks, a professional portrait session and a night out on the town, with proceeds going to community outreach; free third annual Artisan’s Asylum Winter Open Studios, from noon to 6 p.m. Saturday and noon to 4 p.m. Sunday with dozens of makers, engineers, jewelers, crafters and artists with demonstrations and studios full of unique artwork, “really weird lamps, even weirder bikes, robots, collages, R2-D2 and other crazy shenanigans”; Vernon Street 40th Anniversary Open Studios from noon to 6 p.m. Saturday and Sunday at Vernon Street Studios, 6 & 20 Vernon St., Somerville, with artists selling fine art and craft media including painting, photography, prints, sculpture, glass, fiber, jewelry, furniture and ceramics; and a Holiday Boutique from 10 a.m. to 4 p.m. Saturday at the International School of Boston, 45 Matignon Road, with a pop-up store of global arts, crafts (including photographs, sculptures, jewelry and accessories) and specialty foods (including a Café des Artistes and a chocolate surprise) from artists and vendors from around Greater Boston, sponsored by the Parent-Teacher Organization of the International School of Boston, with 20 percent of sales donated to the ISB Academic Enrichment Program.

“Boyhood” at 8 p.m. Saturday at the Massachusetts Institute of Technology’s Building 26-100, also known as the Compton Laboratories, at 60 Vassar St. Admission is $4.

Director Richard Linklater’s “Boyhood” was shot over a dozen years and tells the story of a young boy (Ellar Coltrane) as he matures and deals with divorced parents. Linklater staple Ethan Hawke is part of the cast, as well as Linklater’s daughter, Lorelei, and the film has a perfect 100 score from Metacritic (dropping to an 8.1 user score) and a 99 percent fresh score on Rotten Tomatoes (dropping to an 89 percent audience score). The film series is sponsored by the MIT Lecture Series Committee.

Teddy Bears on Display Party with Santa, caroling and treats from 2 to 4:30 p.m. Sunday at Out of Town News, Zero Harvard Square. Free.

The Harvard Square Business Association and Salvation Army have organized dozens of volunteers from Cambridge, Somerville, Arlington and neighboring communities to dress teddy bears in wedding gowns, tutus, firefighter uniforms, pajamas and other costumes for display in the heart of Harvard Square before going home with more than 350 area youngsters. Santa Claus will pose for pictures, there will be songs from Cambridge Historical Tours’ Victorian carolers and complimentary hot chocolate from Kennedy’s on the Square, 15 Dunster St. Association staff will be on hand to accept nonperishable food items for the Salvation Army food pantry. The teddy bears are on display from 2 to 4 p.m.; Santa Claus visits from 2:30 to 3:30 p.m.; caroling runs from 3:15 to 4:30 p.m.; and there’s hot chocolate from 2:30 to 3:30 p.m. Information is here.

Festivus of Comedy 2014 from 3 to 11 p.m. Sunday at the Davis Square Theatre, 255 Elm St., Somerville. Tickets are $10 for the 3 p.m. family-friendly show; and $15 for the 7 and 9 p.m. shows.

Kitsch In Sync Improv Comedy brings back its annual Festivus of Comedy, inspired by and following the “Seinfeld” holiday traditions: the family-friendly Airing of Grievances, with Kitsch In Sync alumni; Feats of Strength, with Julie K. doing stand-up, Cuddle Party Improv and the Kitsch In Sync main show; Festivus Miracles, with Gypsy Howling Wolf doing stand-up, Liquid Fun Improv from Boston University and more Kitsch In Sync main show. (Each show is about 90 minutes long, and the family-friendly show has an intermission.) The troupe will be collecting for Toys for Tots, and donated toys should be packaged and unwrapped. Information is here.

“Griffelkin” from 5 to 8 p.m. Sunday at the Massachusetts Institute of Technology’s Kresge Auditorium, 48 Massachusetts Ave. Tickets are $5 general admission, or free for members of the MIT community reserving space in advance with institute email addresses.

This three-act opera by American composer Lukas Foss brings together the MIT Concert Choir and MIT Chamber Chorus under the direction of William Cutter and Lynn Torgove to tell the story of Griffelkin, a child-devil.On his 10th birthday in Hell, Griffelkin gets the gift of a trip to the world. Armed with a bottle of magic liquid, he arrives in Manhattan, where has been charged with changing the world into Hell – but his mission is corrupted when he discovers all things human, including love, motherhood and death.