Website-inspired Off Broadway play “Old Jews Telling Jokes” will bow Off Broadway in an open-ended commercial run that kicks off in May.Co-created by Peter Gethers, the scribe-editor and Random House Films prexy, and journo Daniel Okrent, “Old Jews” is a five-thesp revue of jokes and songs both old and new. Marc Bruni, helmer of the upcoming Encores! staging of “Pipe Dream,” directs. Based on website OldJewsTellingJokes.com, the show hits Off Broadway in a production backed by Tom Viertel, Marc Routh, Richard Frankel and Steven Baruch, producers of the upcoming Rialto tuner “Leap of Faith” as well as past outings “A Little Night Music,” “Company” and “Sweeney Todd,” among others. Cast has yet to be announced for “Old Jews,” which begins previews May 1 ahead of a May 20 opening at Off Broadway’s Westside Theater.