I don't remember when Opalang was started, but I joined the project in 2008 :) Fwiw, back then the name was Opa. Opages was the name of the CMS written in Opa/Opalang.
Funnily, Opa and Ur/Web were two projects started around the same time and sharing very similar ideas, and they also collided linguistically – in German, Opa == grand-dad, while Ur == ancestor.
Anyway, have fun with Opal.rb :)
https://github.com/opal/opal/commits/master?page=107 https://github.com/MLstate/opalang/commits/master?page=126