author, The Well-Grounded Rubyist
David A. Black is a Lead Developer and Team Lead at Cyrus Innovation, and a long-time Ruby programmer, author, trainer, speaker, and community organizer. He is the author of the popular book The Well-Grounded Rubyist, and was a founder and long-time director of Ruby Central, the parent organization of RubyConf and RailsConf. David is the chief author of scanf.rb in the Ruby standard library, and maintains the website ruby-versions.net, which offers free shell accounts with access to Ruby versions back to 1.0.