These crawls are part of an effort to archive pages as they are created and archive the pages that they refer to. That way, as the pages that are referenced are changed or taken from the web, a link to the version that was live when the page was written will be preserved.
Then the Internet Archive hopes that references to these archived pages will be put in place of a link that would be otherwise be broken, or a companion link to allow people to see what was originally intended by a page's authors.
Expectations were sky high when Barack Obama was elected president in 2008. As his term draws to a close, has he disappointed or delivered? Novelists in America appraise him
Attica Locke and Esi Edugyan, in conversation: ‘There is so much of our existence that has not been heard’