If Javascript is so great then why do we need Coffeescript?

Consider that in the browser, JavaScript is (with a few minor exceptions) the closest to a universal scripting runtime/VM that we can get. Targeting the browser, therefore, requires compiling down to JavaScript. So JavaScript (the language) and CoffeeScript can both be awesome in the way that Scala and Clojure have their different niches on the JVM.

Coffeescript is Javascript. Just another syntax.

We don't.

Html/js is good for some UI parts of an app but eventually makes one yearn for native threading/locking, queueing, posting notifications, for that last 10-20% of code.

Is this better than Google GWT?

Could one build something with the same graphics and responsiveness like Googles "Speed Tracer" plugin which is way cool?

http://code.google.com/webtoolkit/speedtracer/

It depends. There are a group of people who dislike Java so whatever the arguments are, they will not see SC or Cappuccino better than GWT.

GWT has typical Java attributes/properties: lots of tools and libraries, growing communities, a bit verbose, some setups, a bit heavy (not performance, but from a developer perspective).

The irritating thing with GWT it that it takes a long time to compile.

Its fine. Downloaded the pdf. Its straightforward. Good examples. The topic of graphs is so interesting. Its more fun, as you read, to think about how this can describe real world networks like facebook friends, traffic patterns on a gmap, internet routers, world trade patterns.

As a note, its still being written. The later chapters are not even written at all, they just have notes of topics to be covered.