Python 2.6
Because of the compatibility issue, the releases of Python that lead up to 3.0 play a much more significant role in the transition. Of particular note is Python 2.6, the first and most pivotal of such releases. It represents for users the first time that they can start coding against the 3.x family of releases, as many 3.x features have been backported to 2.x. Whenever possible, Python 2.6 incorporates new features and syntax from 3.0 while remaining compatible with existing code by not removing older features or syntax. Such features are described in "What's New in Python 2.6."