Does the '@' symbol have special meaning in Javascript, Coffeescript or Jquery?

Since the design of CoffeeScript a couple of years have passed and not everything which was proposed in CoffeeScript made it into ECMA script. Instead of being used as a shortcut for this, it's proposed to be used for decorators.

@ is not a valid character for a javascript identifier. Identifiers may only contain $, _, digits and letters.

In coffeescript, @ means this.

CoffeeScript has a few nice features related to the this keyword. First, CoffeeScript uses the @ symbol as shorthand for this.. For example, @foo is equivalent to this.foo. Second, if you use the @ symbol in the parameters of a function, CoffeeScript will automatically assign those values as properties of the object.

Edit: As far as jQuery is concerned, the same identifier rules as javascript apply since jQuery is just javascript. For other uses of @ in jQuery, see this question or the docs.

@ is shortcut for this in coffeescript

So

self = @

is coffeescript for:

var self = this;