Blackboard , the maker of learning and education software for enterprises and schools, announced today that it is being acquired by a group of investors led by Providence Equity Partners , a private equity firm that specializes in media, entertainment, communications and information investments. Providence has also invested in several for-profit educational companies, like Education Management Corporation and Archipelago Learning. The acquisition is an all-cash deal valued at $1.64 billion, with Providence assuming approximately $130 million in Blackboard debt.