Excerpted from a press release:

The largest collection of Darwin’s writings ever published will appear on the website The Complete Work of Charles Darwin Online (http://darwin-online.org.uk/) on 19 October 2006. Never before has so much Darwin material, and so many rare and widely dispersed items, been brought together in one place and made available free of charge. This site currently offers more than 50,000 pages of searchable text and 40,000 images of both publications and transcribed manuscripts. Most of the materials are available both as fully formatted electronic text and colour images of the originals. Darwin’s works are also available as free machine-read audio mp3 files.

As vast as the collection now is, there is much still to come. The site currently contains about 50% of the materials that will be provided by 2009, the bicentenary of Darwin’s birth and the 150th anniversary of the publication of the Origin of species. Forthcoming materials include further editions and translations, images of the majority of the Darwin Archive at Cambridge University Library, more editorial introductions, notes, transcriptions and technical facilities for printing and larger images. New content is continually being added.