The 2 million pound ($3.3 million) project is being funded by the Polonsky Foundation, which aims to democratize access to information.
"We want everyone who can to see these manuscripts, these great works of humanity," Monsignor Cesare Pasini, the prefect of the Vatican Library, said in an interview Tuesday inside the frescoed library. "And we want to conserve them."
Among the first works up on the site Tuesday, at http:/bav.bodleian.ox.ac.uk, are the two-volume Gutenberg Bibles from each of the libraries, an illustrated 11th-century Greek Bible and a beautiful 15th-century German Bible, hand-colored and illustrated by woodcuts.
The Vatican Library was founded in 1451 and is one of the most important research libraries in the world. It has 180,000 manuscripts, 1.6 million books and 150,000 prints, drawings and engravings. The Bodleian is the largest university library in Britain, with more than 11 million printed works.
Pasini said the Vatican was embarking on similar digitization projects with libraries in Azerbaijan and China, among others.