Check out this piece from Tim O’Reilly. The O’Reilly people track sales trends in tech books, not just their own but the whole industry. They’re transparent about their methodology and in my opinion these numbers are very solid and believable. Anyhow, in this case, you need to read the narrative that goes along with the picture. The growth is being driven by the OSS+Java stuff: Spring, Struts, Lucene, and so on. Hey Tim, how about doing middle-aged eyes a favor and making future versions of the graph a little bigger?