Matthew Helmke has been an Ubuntu user since April 2005 and an Ubuntu Member since August 2006. He served from 2006 to 2011 on the Ubuntu Forum Council, providing leadership and oversight of the Ubuntu Forums, and spent two years on the Ubuntu regional membership approval board for Europe, the Middle East, and Africa. He has written articles about Ubuntu for magazines and Web sites, is the lead author of Ubuntu Unleashed, and has written several books and articles on other topics.

Elizabeth K. Joseph is a professional Linux Systems Administrator currently working at Hewlett-Packard, with a focus on managing the infrastructure for the OpenStack project. She has been working with Linux and around Linux communities since 2002. Elizabeth began contributing to Ubuntu in 2006 and currently contributes to various teams, including Documentation, News, Quality Assurance, and Classroom. Over the years she has served on the Ubuntu Membership Board and is now serving her third term as a member of the Ubuntu Community Council. At home in San Francisco, she serves as one of the leaders of the Ubuntu California team and is on the board of a nonprofit that provides Ubuntu-based computers to schools in need.

José Antonio Rey is a community contributor who has been actively participating since 2011. He is a student residing in Peru, whose contributions include helping with the News and Classroom teams, managing Ubuntu On Air!, and being the contact of the Ubuntu Peru team and a member of the LoCo Council. Even though he is not a developer, he has helped with Juju charms and is the author for the Postfix and Mailman charms.

Philip Ballew is an active open source advocate in the greater open source community. He is heavily involved in the Ubuntu project, and spends most of his time contributing to this project. When Philip is not contributing to Open Source, he can be found riding his bike, dancing badly, or attempting to pass his college classes. Philip is eager to get involved in any project that he sees making a difference in the world for the good, and enjoys Ubuntu for this reason. He currently calls sunny San Diego, California, home, and hopes all readers of the book come by and say hello to him there.

Benjamin Mako Hill is a long-time free-software developer and advocate. He was part of the founding Ubuntu team whose charge at Canonical was to help grow the Ubuntu development and user community during the project's first year. Mako is an Assistant Professor at the University of Washington and a fellow at the Berkman Center for Internet and Society at Harvard University. He holds a Ph.D. from MIT.