Ansible 2.0 Has Arrived
www.ansible.com/blog/ansible-2.0-launch
From the page
Saved with the link. Notes from 2007 to 2016 are mostly the page's own words, so this is probably an excerpt.
Ansible 2.0 is quite a bit more than a large refactoring effort. The cleaner architecture allowed us to add several new features we had been considering for a while, plus one which became possible directly because of the refactoring.