This is as days pass by, by Stuart Langridge

A list of free tech books from Simon Willison. I love all this. I read etexts all the time, and having really useful resources like this available on the net is a real help. One that I'd personally add is the W3C specs, if you're involved in web development. They're impenetrable at first, and not the things to learn from, but if you're already up on the subject and need a reference for all the little bits you've forgotten then they're indispensable.