[chromatic]

AFAICT, O'Reilly's first Ruby book was "Ruby on Rails", published 2006. O'Reilly's "The Ruby Programming Language" wasn't published until 2008.

O'Reilly published Matz's Ruby in a Nutshell in 2001, but it didn't sell very well. When I worked there, I encouraged more Ruby publishing but only after I published the "Rolling with Ruby on Rails" articles (January 2005) did that argument get much traction.

The Pragmatic Programmers released their first Ruby programming book in 2000, by way of comparison (and Dave introduced me to DHH in 2004, which is how I decided to seek out the Rails articles).