In order to improve the learning process for students with different pre-knowledge, personal characteristics and preferred learning styles, a certain degree of adaptability must be introduced to online courses. In learning environments that support such kind of functionalities students can explicitly choose different paths through course contents or can be directed to different parts of the instructional material depending on the pace of their advancement in acquiring new knowledge. This paper presents the implementation of such an environment by extending open source learning management system Moodle.