I am interested on a system, able to control the access of users by passwords, which could be free. I mean a place in which as teacher I do not have to pay but can control the access of students to my lectures.
an alternative that I have used is the Joomla CMS . Free and easy to use. You can control the entire interface without much programming, and have control over user access.
Hi Alfonso,mtry Edmodo. Layout simular to facebook, which is familiar to students, but very well controlled by the teachers, parents and students. You can also reward participation by giving some medals.