Rather than merely test for code correctness, Exercism uses peer review to improve general programming techniques. Users are encouraged to comment on others' solutions, and refine their own based on feedback.
Unlike many code practice websites, Exercism requires the user to develop and test entirely offline, submitting only the finished code. This promotes familiarity with essential tools and workflow, not just the bare language.
It's best to have at least a basic understanding of programming before tackling the exercises on exercism.io. You also have to know how to set up your development environment, as you will be coding everything locally (versus websites that provide you an editor right in the browser).
Exercism requires using a CLI utility to fetch and submit exercises. This is inconvenient compared to web-only alternatives, and poses an additional barrier to entry for some users.
The site also provides an interpreter right on the page, which will let you run CoffeeScript in your browser, and show you the equivalent JavaScript as you type.
If you're already familiar with JavaScript, The official CoffeeScript website is an excellent resource for picking up CoffeeScript - the main page provides a quick reference for all of the language's features, complete with examples, side-by-side with their JavaScript equivalents.
If you're the type who likes to really dive into the details of the tools you use, the CoffeeScript website also provides clearly annotated source for the language itself, to clear up any questions you might have.
Videos give an overview of the course/lesson plan before a single line of code is written. This gives context and a general understanding of what is possible and how teaching will be approached.
After each video, there are a series of challenges that give you a chance to apply what you just learned. The great thing about these challenges are that they force you to think through a problem, and use the new skills to solve it. It's not just regurgitating facts; it requires some effort.
"The Little Book on CoffeeScript" does not go into depth. Instead, it covers the syntax and all of the available features of CoffeeScript, giving the reader enough knowledge to learn more advanced CoffeeScript with ease.
The Table Of Contents is located at the top only, there is no way to navigate from your current position in the tutorial.
Everything is lumped into the one web page with a limited number of titles/breaks, so it's easy to lose your spot.