CourseWorks is the Columbia course management system. It's a web-based publishing environment that allows you to quickly post syllabi, assignments, and any kind of file (e.g., Word, PowerPoint.) CourseWorks offers many other features such as sending emails to the class and hosting a class-related discussion board.
CourseWorks can be accessed at http://courseworks.columbia.edu. (You need to log in with your Columbia UNI and password).