David Chelimsky is the lead developer/maintainer of RSpec, and has contributed to several other open source projects including Cucumber, Aruba, and Rails. He has been developing software for over a decade, including three years training and mentoring agile teams at Object Mentor. He is currently a Senior Software Engineer at DRW Trading Group in Chicago, IL. In his spare time, David likes to play guitar, travel, and speak something resembling Portuguese.

Dave Astels is the Director of Technology at ChannelFireball.com and has been involved with software and computing for over 25 years, recently having spent several years working exclusively with Ruby and Rails. Dave wrote the article that prompted Steven Baker to start the RSpec project.

Bryan Helmkamp maintains Webrat, a Ruby library to implement acceptance tests for web applications in an expressive and maintainable way, and is an active participant in the New York City Ruby community. Bryan is the CTO of Efficiency 2.0, a startup that helps people understand and reduce their energy use.

Dan North writes software and coaches teams and organizations in agile and lean methods. He believes that most problems that teams face are about communication and understanding, which is why he puts so much emphasis on "getting the words right." In 2003-4 this led him to develop the ideas that would become Behaviour-Driven Development. He is delighted by the community that has grown up around RSpec and Cucumber, and especially the enthusiasm and dedication of their core contributors. Dan is currently a Senior Software Engineer at DRW Trading Group in London, where he gets to actually code again!

Zach Dennis is a co-founder and fellow human at Mutually Human Software, an expert custom software strategy and design consultancy in Grand Rapids, Michigan. He has been enjoying Ruby for nearly eight years and has contributed to several projects such as Ruby's standard library documentation, Ruby on Rails, and RSpec. In his spare time, Zach loves spending time with his family, continuously learning, playing music, and running continuousthinking.com.

Aslak Hellesoy is a Senior Software Engineer at DRW Trading Group in London. While contributing to this book he was the Chief Scientist of BEKK Consulting in Oslo. In 2003, after seven years of professional Java programming, he fell in love with Ruby. He has contributed to dozens of open source projects and is the founder of the Cucumberproject. Aslak likes to cook, ski, and travel.