Hey guys, I am using solo learn from past 6 month, solo learn is very easy and informative site, you must try if you want to learn some programming languages.
Information depth-You have to choose which language you want to learn then start your course with simple introduction to detail information about that course, with every chapter end there will be a exam you have to clear it to get next chapter. You can get deep knowledge about any language in solo learn.
User friendly-yes, solo learn is totally user friendly it gives you support, suggestions to make your better and the interface is also very decent.