When comparing Pro Git vs Hackr.io, the Slant community recommends Pro Git for most people. In the question“What are the best resources to learn git?” Pro Git is ranked 1st while Hackr.io is ranked 10th. The most important reason people chose Pro Git is:
Although the book is free online, you can support the author by purchasing a [hard copy of the book](http://www.amazon.com/Pro-Git-Scott-Chacon/dp/1430218339/ref=sr_1_1?ie=UTF8&qid=1373668887&sr=8-1&keywords=pro+git).
Ranked in these QuestionsQuestion Ranking
Pro Available for free online
Although the book is free online, you can support the author by purchasing a hard copy of the book.
Pro Comprehensive and clearly written
The book is a comprehensive guide on everything you need to know to learn and master Git. It starts with the basics, but also moves into the deeper complexities of Git, not only explaining what commands do, but how.
A strong understanding of the inner mechanics of Git will help you use them to perform very powerful operations in keeping track of your code history, and developing features.
Pro Available in many languages
Pro Community trust
Instead of getting a recommendation from a single dev, you get recommendation from the entire programming community.
Pro Recommendation for every programming language/framework/library
You can find Python as well as Jenkins.
Pro Nice filters
Free, Video, Book, Beginner, Advanced, etc.
Con May be intimidating for beginners
It's an excellent treatment, but it may not be the place a new person wants to start. (At least reading cover-to-cover.)