Yehuda Katz is a member of the Ember.js, Ruby on Rails and jQuery Core Teams. His 9-to-5 home is at the startup he founded, Tilde Inc., where he works on Skylight, a Rails performance tool. Yehuda is the co-author of best-selling jQuery in Action and Rails 3 in Action. He spends most of his time hacking on open source—his main projects, along with others, like Thor, Handlebars and Janus—or traveling the world doing open source evangelism work. He blogs at http://yehudakatz.com and can be found on Twitter as @wycats.