Boston Ballet and American Repertory Theater are planning a major collaboration. ART artistic director Diane Paulus and Boston Ballet artistic director Mikko Nissinen are working together to develop a new take on Molière’s “Le Bourgeois Gentilhomme,” to be performed at the Opera House in the spring of 2015. Karole Armitage, a Tony nominee for her work in Paulus’s Broadway production of “Hair,” will serve as choreographer, and the writer will be Taylor Mac, known in these parts for his show “The Lily’s Revenge,” which was performed at the ART last year. “I have always been a huge fan of the ART so this was a natural collaboration,” said Nissinen. “Diane and I share a mutual interest in creating something revolutionary and new.” If you’re curious about Armitage, her company Armitage Gone! Dance performs at the Institute of Contemporary Art Friday through Sunday.