"Baen Books is now making available — for free — a number of its science fiction 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.)"
These are not unpublished manuscripts and Eric Flint has been doing this since 2000. There are titles by Andre Norton, Lois McMaster Bujold, Larry Nivin, and Fred Saberhagen to mention some of the names I recognize.