jQuery's understandability is part of its superiority over MooTools. When I was first looking for a Javascript library years ago, it was better documented than

jQuery's understandability is part of its superiority over MooTools. When I was first looking for a Javascript library years ago, it was better documented than other libraries, it was more readable (particularly method names), and didn't lean towards OOP (I admit I personally hated Java). MooTools and other libraries might possibly be more powerful if you are developing in Javascript in general, but for web development I primarily care about DOM manipulation, and it was much easier to pick up jQuery than anything else at the time. It's a mistake to think that languages should win out simply based on functionality and capabilities, without taking into account things like ease of use and learning curve.