BOSTON--(BUSINESS WIRE)--Global learning company Houghton Mifflin Harcourt (HMH) today announced the launch of a new online Developer Portal, in which edtech developers, designers and educators can leverage newly-exposed HMH APIs to create learning applications that meet the evolving needs of today’s students, teachers and parents. To mark the launch, HMH will host its inaugural Curious Codefest, a 24-hour developer challenge in the Company’s HQ city of Boston on June 27-28, 2015. The HMH Devel