The success of the e-learning paradigm observed in recent times has created a growing demand for e-learning systems in universities and other educational institutions, which has itself led to the development of a number of either commercial or open-source Learning Management Systems (LMS). While the usage of these systems gains recognition and acceptance amongst institutions, there are new problems arising that need to be solved. Because of multiplicity of platforms and approaches for systems implementation, it becomes increasingly difficult to manage or compare them. Each new LMS presents its own learning model. How to compare different e-learning platforms, and on what basis to choose the most adequate one, is a task of ever increasing importance. This paper describes and compares some widely used open-source e-learning platforms (Docebo, Moodle, Dokeos, Claroline, Atutor and Ilias) from the point of their adaptivity.