Open educational resources (OER) are seen as means to decrease the cost of higher education and close the educational divide between different society groups. At the same time, studies show that collaborative learning is very beneficial for the students. The effective organization of collaborative learning activities is, however, a complex task that requires both properly structured instructional materials and an appropriate collaboration management system. In this paper we discuss the design and development of a free-to-use software system that stimulates the employment of OER in the preparation of collaborative learning materials for mobile devices or lab computers. The system is web-based and enables instructors to coordinate the collaborative learning process more effectively. It also collects data for assessment of student attainments and employs mark up and tagging for tracking and rights management. The system focuses on interactions based on gap filling activities and is particularly suitable for learning in small groups, e.g., group learning about case studies in business classes. Observations and comments regarding the use of the system in an operations management course environment are summarized in the end of this work.