(from Intro, by Eric Flint)
"Baen Books is now making available — for free — a number of its titles in electronic format. We're calling it the Baen Free Library. Anyone who wishes can read these titles online — no conditions, no strings attached. (Later we may ask for an extremely simple, name & email only, registration. ) Or, if you prefer, you can download the books in one of several formats. Again, with no conditions or strings attached. (URLs to sites which offer the readers for these format are also listed. )..."
Basically, Baen has (for several years now in fact) put a very large number of their books into the online free book library, allowing anyone to come download a free copy of their works. Predominantly, Sci-Fi/fantasy, there are some hidden gems in the mix, as well as some rough cut oddities.