Project Gutenberg is convinced that proofreading by human beings is a very important step, and that this step makes all the difference. The use of scanned books as is --converted to text format by OCR software with no proofreading-- gives a much lower quality result. After running OCR software, the text is 99% reliable, in the best of cases. After proofreading, the text becomes 99.95% reliable (a high percentage which is also the standard at the Library of Congress). For this reason, Project Gutenberg's perspective is rather different from that of the Internet Archive. In its Text Archive, books are scanned and "OCRized", but they are not proofread. The main formats used are XML, TIF and DjVu. Books are not proofread either in other main collections: Open Content Alliance (OCA), Google Books Search or Microsoft Live Books Search. Project Gutenberg provides a "Nearly Full Text" search (on the first 100 K of each file) using Google, with a database updated approximately monthly. It also provides a search of book metadata (author, title, brief description, keywords) as a participant in Yahoo!'s Content Acquisition Program, with a database updated weekly. Both are available in the Online Book Catalog (at the bottom of the page). In the Advanced Search, several fields can be filled: author, title, subject, language, category (any, audio book, music, pictures), LoCC (Library of Congress Catalog classification), filetype (text, PDF, HTML, XML, JPEG, etc.), and eText/eBook No. A field "Full Text" was also added as an experimental feature. On Project Gutenberg's website, a File Recode Service allows users to convert books in one format (ASCII, ISO-8859, Unicode and others) into another, and vice versa. A much more powerful conversion program may be launched in the future, with a conversion into still more formats (XML, HTML, PDF, TeX, RTF), including Braille and voice. It will then also be possible to choose the font and size of characters and the background color. Another eagerly expected conversion is that of a book from one language to another by machine translation software. This may be possible in a few years, when machine translation is accurate to 99%. Still, these books will certainly need some proofreading too by human translators. 4. SHARED PROOFREADING The main "leap forward" of Project Gutenberg in the last few years is due to Distributed Proofreaders. Distributed Proofreaders was launched in October 2000 by Charles Franks to help in the digitizing of public domain books. Originally meant to assist Project Gutenberg in the handling of shared proofreading, Distributed Proofreaders became the main source of Project Gutenberg books. In 2002, Distributed Proofreaders became an official Project Gutenberg site. In May 2006, Distributed Proofreaders became a separate entity and continues to maintain a strong relationship with Project Gutenberg.