List comprehensions. Distinct 'of' (property) and 'in' (value) operators. Bind a function to current 'this' with =>. Nothing winds up in global scope unless you mean it. Use reserved words as property names. Existential operator and assignment. Always use '==='. Everything is an expression:
value = switch value
when 1 then one
else whatever
Closures.
do (value) ->
#value is wrapped in a closure
The 'class' macro.
And that's just off the top of my head. Yes, it compiles to JavaScript. You could write all this by hand. It would be a waste of your time-- CS writes safe, efficient, readable code faster and better than you do, every time.
Peoples' obsession with CS having the class macro is weird to me. Seems like laziness more than anything - once I grokked JS's protoype object model I've found it to be ridiculously powerful AND I got to learn a cool new programming abstraction at the same time. All the rails guys I know are going gaga over CS but I just don't see the point as I like and can be efficient in JS.
I can't speak for anyone else, but I treat the class macro as pure shorthand. I understand implicitly that "properties" in a "class" are being assigned one at a time on the constrictor's prototype, and frequently use that knowledge for metaprogramming. You call it laziness; I call it nicer syntax.
I understand that puts me in a small boat. In my opinion, people shouldn't use the class macro without knowing what it really does. Actually I'd extend that to say people shouldn't use CoffeeScript at all without an understanding of the JavaScript it compiles to, just as you shouldn't use C without an understanding of the assembly it compiles to... But that's probably wishful thinking. It wouldn't be an improvement for those people to write assembly (or raw JS) instead.
And that's just off the top of my head. Yes, it compiles to JavaScript. You could write all this by hand. It would be a waste of your time-- CS writes safe, efficient, readable code faster and better than you do, every time.
Look harder.