Hi.
I wanted to read this book https://www.amazon.com/Moodle-Extension-Development-Jonathan-Moore-ebook/dp/B0058O84U6 for learning how to create blocks, plugins and other stuffs.
( I know that a new book is published but I can't afford it right now )
But the problem is that it is for version 1.9 and we are on version 3.3.
How much Moodle backend has been changed since then? Can I still read and learn from it?