FutureLearn, a subsidiary of The Open University, offers a wide range of free online courses. FutureLearn offers online courses on academic topics in history, science, literature, and political science. You will also find FutureLearn courses on topics like public speaking, developing a resume, and digital marketing. Courses range in length from two weeks to eight weeks. Some of the courses, like this public speaking course, require you to submit assignments to participate.
One of the FutureLearn courses that I am interested in taking is this six week course on Hadrian's Wall. The complete list of scheduled courses is available here.
Applications for Education
FutureLearn could be a good place to find a course to help you meet your professional development needs. For example, the Hadrian's Wall course will help me further my knowledge in that area which in turn should help me develop better lessons for my students.
FutureLearn could also be a good place to find courses for students who have an interest in a topic that your school doesn't offer courses in.