WeBWorK Open Problem Library (OPL)
The WeBWorK Open Problem Library (OPL) contains problems contributed by faculty from many institutions that have used WeBWorK. Currently, there are approximately 35,000 problems in the OPL, and new problems are added regularly. The OPL was initially formed from several of the original File Based Problem Libraries, and includes all of the problems from the Arizona State, Rochester, California State-Long Beach, and the University of Virginia libraries. It also contains most, if not all, of the problems from Union College, the College of New Jersey, Dartmouth, Ohio State, Northern Arizona University, and Indiana University. Once known as the National Problem Library (NPL), the Open Problem Library (OPL) naming convention was adopted in the summer of 2012 to accommodate the increasing internationalization of WeBWorK and the possible inclusion of problem libraries from textbook publishers.