Funded since 2001 by National Science Foundation, an innovative open courseware (http://nm.mathforcollege.com) has been developed for a comprehensive undergraduate course in Numerical Methods. The open courseware resources enhance instructor preparation and development as well as the student educational experience by facilitating a hybrid educational approach to the teaching of Numerical Methods, a pivotal STEM course, via customized textbooks, adapted course websites, social networking, digital audiovisual lectures, concept tests, self-assessment of the level of learning via online multiple-choice question tests and algorithm-based unlimited attempt quizzes, worksheets in a computational system of choice, and real-life applications based on the choice of one's STEM major. The resources have been implemented successfully at the University of South Florida, Arizona State University, Old Dominion University, Milwaukee School of Engineering, and Mississippi Valley State University. With philosophies of open dissemination and pedagogical neutrality, more than 30 institutions and thousands of individual users have adopted the resources in an a la carte fashion. In this paper, we discuss the history, philosophy, development, refinement, assessment process, and future of the open courseware. The summarized assessment results include those of comparing several instructional modalities, measuring student learning, effect of collecting homework for a grade, using online quizzes as a substitute for grading homework, interpreting summative ratings of the courseware, student satisfaction, and Google Analytics.