MARJORIE PRIME Jordan Harrison’s intriguing drama, a 2015 Pulitzer finalist, ventures to a not-too-distant future when the boundaries between technology and humanity have become so blurry that we entrust our memories to artificial-intelligence programs that have assumed the form of deceased loved ones. Directed by M. Bevin O’Gara. Through Oct. 9. Nora Theatre Company. A Catalyst Collaborative@MIT Production. At Central Square Theater, Cambridge. 617-576-9278 ext. 1, www.centralsquaretheater .org

SIGNIFICANT OTHER In Joshua Harmon’s comically incisive journey across the jagged landscape of 20-something friendship, dating, and love, Greg Maraio (pictured, with Kathy St. George) delivers a multifaceted performance as Jordan, a single gay man who feels adrift when his three female friends start getting married. Directed by Paul Daigneault. Through Oct. 8. SpeakEasy Stage Company at Roberts Studio Theatre, Calderwood Pavilion, Boston Center for the Arts. 617-933-8600, www.speakeasystage .com

REGULAR SINGING This is the fourth and final installment of Richard Nelson’s Apple Family Plays, and it’s a beauty, a kind of collective meditation on the vexations and consolations of family, along with a few minor matters like death, memory, and history. The production features the same first-rate cast as the previous three plays, meshing as smoothly as a well-honed chorus, and is directed by Weylin Symes, who was also at the helm for “That Hopey Changey Thing,’’ “Sweet and Sad,’’ and “Sorry.’’ Through Sept. 25. New Repertory Theatre in association with Stoneham Theatre at Charles Mosesian Theater, Arsenal Center for the Arts, Watertown. 617-923-8487, www.newrep.org

DON AUCOIN

Don Aucoin can be reached at aucoin@globe.com.