Ruby Association has operated the exam to certify a programmer for Ruby three times since October, 2007. The association has organized the paper based exam only in Japanese and at two cities in Japan so far; however, the exam will be improved vastly from January. According to the article reported about extension of the exam on January 22, 2008, Prometric is responsible to the exam (Press Release in Japanese) from the beginning of the year and the first CBT Ruby exam is scheduled in February. Prometric will start English version of this exam in the end of April this year in 135 countries all over the world.
Paper based old exam of a certified programmer for Ruby had fifty multiple-choice questions for ninty minutes. This web site(Japanese only) has helped examinees from the first exam and advices them to study with the book , Programming Ruby: The Pragmatic Programmer's Guide, 2nd Ed.