He wrote the first one (Learn Python the Hard Way) and a few others. He actually emailed me and asked me to write Learn Java the Hard Way. In his words (paraph

He wrote the first one (Learn Python the Hard Way) and a few others. He actually emailed me and asked me to write Learn Java the Hard Way. In his words (paraphrasing, since this was from a phone call): "I was a professional Java programmer for eight years and now I can't stand Java. There's no way I could deal with it long enough to write a Java textbook."