Rael Dornfest is an American computer programmer and author. He is UX engineer of Twitter, and was formerly the Chief Technology Officer at O'Reilly Media. He began working for Twitter after they bought the assets of his company Values of N.
He led the RSS-DEV working group, which authored RSS 1.0 and is the author of Blosxom, a lightweight Perl-based publishing system.
He is Series Editor of O’Reilly's Hacks series, and has co-authored a number of books including Google Hacks (ISBN 0-596-00447-8), Mac OS X Panther Hacks (ISBN 0-596-00718-3), and Google: The Missing Manual (ISBN 0-596-00613-6).