Yehuda Katz is a member of the Ember.js and jQuery Core Teams; during the daytime, he works at Tilde. Yehuda is the co-author of the best-selling jQuery in Action, Rails 3 in Action, and is a contributor to Ruby in Practice. He blogs at yehudakatz.com and can be found on Twitter as @wycats.
Jon Leighton is Tech Director at Loco2. During his time on the core team he did a bunch of work on Active Record and created the Spring preloader. These days he spends lots of time rock climbing. You can follow @jonleighton.
Josh Peek (joshp) has been working with almost all parts of Rails. A lot of work spent on performance and thread safety for Action Pack. Josh works at GitHub.
Carl Lerche is a Platform Architect at Strobe, where he runs a top-notch product engineering team and hacks on Strobe Platform. He’s been programming for as long as he can remember, and focused on Ruby development since 2005. He is a member of the Ruby on Rails Core Team and speaker at numerous industry conferences and events. He lives in downtown San Francisco and has a fondness for quality Belgian Beers... and pie. Follow him on Twitter at @carllerche.
Pratik Naik (lifo) stumbled upon Rails back in 2006 while in search for a better web framework after 2 painful years with perl/mod_perl. He hasn’t looked back since then. Currently located in London, he is an employee of Basecamp and maintains a personal blog at http://m.onkey.org.
Jamis Buck (minam) is a repentant Java programmer who never really enjoyed Java, but who finally found web-programming joy in Rails. He is an avid Ruby programmer, having contributed several packages to the community (including Net::SSH, Net::SFTP, Syntax, sqlite-ruby, sqlite3-ruby, SwitchTower and others). He lives with his wife Tarasine and four children in Idaho.
Marcel Molina Jr. (noradio) is a language enthusiast who went from being a literature major to a programmer. In his transition from natural language to machine language he found Ruby an elegant balance of dynamic, pragmatic and “humane”. And then came along Rails… Marcel works at twitter and tumblelogs at Projectionist.
Nicholas Seckar (ulysses) is a student and software engineer living in Toronto, Canada. Nicholas has been contributing to Ruby and Rails since Fall 2004, with numerous bug fixes and new features such as Routing. He has been a developer on Measure Map since August 2005. He is currently completing his undergraduate degree at the University of Toronto, while also working for Google in their Toronto engineering department.
Florian Weber (csshsh) began using Rails in early 2004. Since then he’s played an integral role in several Rails-based projects. He developed the CMS and webshop for bellybutton.de, and later worked on Odeo. In Spring 2006 he began working on Twitter as lead developer. At the moment, he is living in Berlin, Germany and working as a software developer.
Scott Barron (htonl) was set to swear off computers forever and become a plumber when Rails was released. He immediately found salvation in the warm embrace of Ruby and has never looked back. He currently practices Rails by working for EdgeCase.
Tobias Lütke (xal) encountered Rails while struggling to find technology for his new company. Once found, he quickly ported the bits and pieces of his code over to Ruby which later became the first rails based e-commerce store “Snowdevil”. Tobi is a partner at JadedPixel and is frantically working on Shopify which is the continuation of the Snowdevil code base. Over time, Tobi released many open source projects such as Typo, Hieraki, and Liquid.