WebCourser is one such evolving system. Instructors often desire to modify existing courses - either to update material, to address a different audience or any one of a myriad of changes.
Good courses tend to evolve over time as course material is reworked.
Web ReCourse, the Web Retargetable Course Generation System facilitates this process. In addition, the true course customization problem is an education in the large problem. The problems of time and space complexity are just beginning to be addressed. It is an education in the small application. In fact, the retargeting problem may need to be understood to make steps towards real solutions of the larger customization problem.