Cambridge University Press is, of course, a very highly regarded imprint offering a multitude of seminal works in philosophy, science, etc. Many titles are now available as eBooks. In its own words: "This year C.U.P. celebrate 425 years of continuous publishing, a year that
also marks the 475th anniversary of King Henry VIII’s grant to
Cambridge University Press of ‘Letters Patent’ allowing us to print
‘all manner of books’. 2009 also sees the 800th anniversary of the
University of Cambridge, providing an occasion for us to join in
celebrating our respective foundations by commemorating the books,
people, ideas and achievements that have emerged from this shared
history and which continue to inspire and transform the world."