Easy to use but also possible to create complex eLearning scenarios. You have so many options, but also without deeper knowledge there are good results.

Chamilo is easy to install It allows you to create simple set courses managed through intuitive tools . It has an excellent system to create courses sessions defined times . It allows a programmed sequence level courses

The best for me in chamilo is that it is easy to install and understand it's code to create new functionalities. It has a lot of configuration to adapt to many different kind of use. And if a specific extension is needed it's easy to implement.