I can freely read, share and modify the book. The only restrictions is that I can't sell it. It's pretty open in my eyes ,even if it doesn't comply strictly to

I can freely read, share and modify the book. The only restrictions is that I can't sell it. It's pretty open in my eyes ,even if it doesn't comply strictly to the definition of this or this organisation. on the same topic, I've seen people say that GPL isn't free for example.