CrossRef Search is available to all users, free of charge, on the Web sitesof participating publishers, and encompasses current journal issues as well asback files. The results are delivered from the regular Google index but filterout everything except the participating publishers’ content, and will linkto the content on publishers’ web sites via digital object identifiers(DOIs) or regular URLs. CrossRef itself does not host any content or performsearches – CrossRef works behind the scenes with Google to facilitate thecrawling of content on publishers’ sites and sets the policies andguidelines governing publisher participation in the initiative. As well asenabling CrossRef Search, the partnership with Google also means that full-textcontent from the publishers is also referenced by the main Google.com index inits more general searches. Participating publishers now include: The CrossRefSearch pilot will run through 2004 to evaluate functionality and to gatherfeedback from scientists, scholars and librarians for the purpose of fine-tuningthe program. Participating publishers are also investigating how DOIs can beused to improve indexing of content and enable persistent links from searchresults to the full-text of content at publishers’ sites. CrossRef is alsoin discussion with other search engines.