David Heinemeier Hansson

Ruby on Rails. Heinemeier Hansson, a Danish programmer working for the small firm that became 37signals, extracted the web framework behind its Basecamp product and released it as Ruby on Rails in 2004. Its conventions over configuration and built-in tools for databases and testing let small teams build web apps quickly, influencing frameworks in many languages. He co-owns 37signals and is known for blunt opinions as well as code.