Squeak is a modern open-source development environment for the classic Smalltalk-80 programming language. This book, intended for both students and developers, will guide you gently through the language and tools by means of a series of examples and exercises. We are making this book available to you under the Creative Commons Attribution-ShareAlike 3.0 license. You can either download the PDF for free from SqueakByExample.org, or you can buy a softcover copy from lulu.com. (You can also pay for the PDF download from lulu.com, if you would like to make a contribution to this effort.) Additional material is available from the book's web page at SqueakByExample.org.
Not what I was expecting at all. I wanted to learn about OOP, using Smalltalk as an example. Instead, the book dives into the nitty-gritty of Squeak and stays at that level. You might say I should have expected Squeak and not Smalltalk, but the book itself uses the Smalltalk object model as reference.
I love that this introduction doesn't just teach the Smalltalk language and Squeak, but also explains the tools and techniques used by the community. So when you're adding methods to classes it will tell you about the testing browser and how to build the method in a test-driven way, and it explains how to do version control with Monticello and push your code to a repository. The code host they recommend no longer allows new projects, but I was able to follow the same instructions to use smalltalkhub.
This book has given me so many ideas about Object-Oriented Programming, not just about using Squeak but anywhere I use it. I'd heartily recommend that anyone who's doing OOP grab Squeak, grab Squeak by Example, and spend the few hours required to work through the book.