Yehuda Katz is one of the creators of Ember.js, a member of the Rust Core Team, and a retired Ruby on Rails and jQuery Core Team member.
His 9-to-5 home is at the startup he founded, Tilde Inc.. There he works on Skylight, the smart profiler for Rails, and does Ember.js consulting.
He's best known for his open source work, which also includes having created projects like Thor, Handlebars and Bundler. He travels the world doing open source evangelism and web standards work.
He blogs at http://yehudakatz.com and can be found on Twitter as @wycats.