Yes, in almost all cases we're digitizing the texts, because in most cases, these are not new books. Typically, a lot of other projects that are putting texts online are trying to sell e-books, or sell copies of new books. Questia is trying to provide a holistic research environment in which students can have access to a world-class collection of content, and it enables them to write better research papers faster and better by providing them with tools that integrate with their word processor. We use the ConText search engine from Oracle. All searching is free, by the way.
Someone coming to the site can do three types of searches.
First there's a quick keyword search on titles, authors, and Library of Congress subjects. Third, users can do a full-text Boolean search, with adjacency, exclusions, etc. It's an incredibly powerful tool that we provide for everyone. We retain the original pagination and even the original line breaks of the books. We do a lot of content tagging.