Alan Dixon has been helping non-profits with their contact databases since 1989. He works as an independent website developer, is based in Toronto, Canada, and has been building websites with CiviCRM since 2006. He maintains the site http://community.civicrm.ca.
David Geilhufe, born and raised in Silicon Valley, focuses on the intersection of technology and social change. He has founded non-profits and for-profits, built the operations of corporate citizenship organizations and private foundations, developed venture-funded enterprise software systems, brought together open source communities, and mentored at-risk youth into high-tech employment. He's always looking to create and execute a big idea that will do a little good for the world.
David currently runs http://netsuite.org/, NetSuite's corporate citizenship program focused on delivering an ultra-low-cost back office solution to charities and social enterprises worldwide.
Mohamed M. Hagag is a Unix/Linux system engineer with free open source software passion. He likes research and development on FOSS, and is working independently and with teams on FOSS R&D since 2004. His current and past employers are small and medium-scale companies working in the IT market in general with some level of UNIX/Linux specialization. Though he hasn't officially worked on any book, he has worked on translating some technical books to Arabic language.
Rico Landman is a web developer from Zwolle, the Netherlands. After working for several companies as a web developer, he started his own company Futurix. He mainly works with PHP and is a devoted open source partisan, excelling in the use of Magento, Drupal, vTiger, and so on.
In the last few years he has tended to seek cooperation with other open-source-oriented companies. Most of his projects reside under Simourix (co-owner) or Trinfinity, an international network of specialists working in the high-end Internet industry.
Eileen McNaughton lives in Wellington, New Zealand where she divides her time between CiviCRM consulting, accounts for the family automotive business, two pre-school super-heroes, and the occasional bit of sleep. She first became involved in CiviCRM while setting up online class registrations for Wellington Circus Trust (for which she is a Trustee) and has been involved in a number of CiviCRM and Drupal implementations for Fuzion since then. She has contributed numerous patches to the Core codebase including payment processors, a custom search, and enhancements to invoices. She has also been working on integration with Xero accounts package and a CiviCRM extension to the popular Drupal Migrate module.
She is a regular voice on the forums and CiviCRM blog, and is driving the Make-it-Happen initiative. She serves on the CiviCRM API and CiviAccounts team, appointments to which are an honor on some days, and bring the word "sucker" to mind on others. Eileen was part of the team that wrote the original CiviCRM Floss manual in the book sprint.