I noticed this question: List of freely available programming books
I feel the question is against Stack Overflow policy. Asking for 'some' or all free programming books is very vague, and will result in a very large amount of "correct" answers. This can be very well seen from the top-rated, compiled answer. I can't really even say if the question is a real question at all.
Seeing that the question is very old and has gained an amazing amount of reputation, it seems the moderators agree that the question is allowed. Can you explain to me why this is a good question? Wouldn't it be better to compile the information to e.g. Wikipedia? Also, will the compiled best answer become outdated at some point or will someone update it ad infinitum?