Apache2 namespace

[Jim Albert]

Can someone point me to a URL that describes the purpose of the Apache2 
namespace? Latest mod_perl was just installed on one of my systems and I 
noticed a few modules moved from Apache:: to Apache2::

Not a big deal. I made a few changes to handle that. But, I'm wondering 
if I should eventually expect all modules to move from Apache:: to 
Apache2:: or what the criteria might be for doing so. For example, it 
looks to me from cpan like Apache::Session still exists in Apache::

Thanks.

--
Jim Albert