Treasures in full: Shakespeare's plays, Chaucer's Canterbury Tales, Gutenberg's Bible

From the British Library, in a section called Treasures In Full ("High-quality digital editions, free to your desktop"):

Examine every page of rare historic works; compare different editions side-by-side; choose standard or magnified view; read supporting material by our curators and other experts.

-Shakespeare in Quarto
-Caxton's Chaucer
-Gutenberg Bible
-Magna Carta
-Renaissance Festival Books - coming soon