We have just released Attrio 0.3. Nearly all core extensions after long discusion in my blog were removed. Also we added new specs and updated missing documentation. Here is a link to Attrio GitHub page:

https://github.com/jetrockets/attrio

P.S. If you still don’t know what is Attrio. Attrio is a library that adds typed attributes to plain old Ruby objects. Read more about it in my blog: http://igor-alexandrov.github.io/blog/2013/05/23/attrio-typed-attributes-for-ruby-objects/.