Why most of the javascript frameworks uses object literals instead of constructors or constructors with prototypes?Will it be non standard ,if somebody uses constructors with prototypes in a new framework.What are the advantages of object literals over constructors with prototypes?
It all depends on the need of the programme you're writing and the way you want to maintain the code base.
When you have objects which get instantiated a lot with shared properties and methods it could be more efficient memorywise to use a constructor and fill its prototype.
When the code is more or less a singleton it is probably more efficient to just make an object and fill it with some methods.
If you would like more information about "patterns" and what they can mean to you you could check out http://addyosmani.com/resources/essentialjsdesignpatterns/book/
Or if you like a regular (e-)book i would recommend http://shop.oreilly.com/product/9780596806767.do