Bill Rauch is in his first season running the Oregon Shakespeare Festival. Rauch says he’s a passionate believer in the resident-company concept. “It’s no coincidence that most of the great works come out of companies,” he says. “They’re essential. We move [away from that] at the risk of the art form.” But, he notes, resident companies are an endangered species in America today. OSF is an exception, with many actors rehired year after year, most on a 10-month contract for the 11-play, eight-month repertory season; 91 actors compose this season’s company, most playing several roles.