Probably not, but that document viewer is the product of the DocumentCloud project, which was at one point headed by Jeremy Ashkenas, and from which Underscore and Backbone.js are derived: http://www.documentcloud.org/opensource

However, like most viewers, the DC viewer is best in its standard view, not its embedded view: http://www.documentcloud.org/documents/338833-cover-letter.h...

edit: Ttough yes, the thumbnail nav to go between different documents is not great, though that's more an issue of the site implementation...probably this is a landing page for the docs that would presumably be direct-linked to elsewhere

Like most viewers, the DC viewer is best when it's gone and I can use a proper pdf viewer.