This release adds support for all the new features and syntaxes in ES2018 that weren’t already possible in CoffeeScript.

• Asynchronous iterators are now supported. You can now yield an await call, e.g. do -> until file.EOF then yield await file.readLine(). Fix #4875: Asynchronous iterators #4893
• Object splats/destructuring, a.k.a. object rest/spread syntax, has been standardized as part of ES2018 and therefore this release removes the polyfill that had previously been supporting this syntax. Code like {a, b, rest...} = obj now outputs more or less just like it appears, rather than being converted into an Object.assign call. Note that there are some subtle differences between the Object.assign polyfill and the native implementation. Fix #4876: remove polyfill for object rest/spread #4884
• The exponentiation operator, **, and exponentiation assignment operator **= are new to JavaScript in ES2018. Now code like a ** 3 is output as it appears, rather than being converted into Math.pow(a, 3) as it was before. Fix #4877: Exponentiation operators #4881
• The s (dotAll) flag is now supported in regular expressions. Regular expressions s (dotAll) flag #4880

http://rawgit.com/GeoffreyBooth/coffeescript/2.3.0/docs/v2/