Backwards incompatible Perl 6 & Python 3.0

Both Perl 6 and Python 3.0 are made backwards incompatible with the previous releases due to the changes made in both languages. It appears that at first, these new versions are going to be much slower (10% +) than their predecessors and will be optimised in the future releases. Python 3.0 was released on 4^th December 2008. Python 2.6 however will be developed and maintained until version 2.9, which is still a few years away. 'A Byte of Python' is a free ebook for those who want to learn Python. It has already been updated for the Python 3.0 language.