When comparing On Lisp vs Hackr.io, the Slant community recommends On Lisp for most people. In the question“What are the best resources to learn Common Lisp?” On Lisp is ranked 4th while Hackr.io is ranked 5th. The most important reason people chose On Lisp is:
A free version of the book can be downloaded on Paul Graham's [website](http://www.paulgraham.com/onlisptext.html).
Ranked in these QuestionsQuestion Ranking
A free version of the book can be downloaded on Paul Graham's website.
Pro Clear language
It's written in an simple, informal, yet articulate style.
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 Not a good starting placing for beginners
This book requires the reader to already have an intermediate-level experience with Common Lisp.