[Serusers] Open Source Billing Software

[Rod Bacon]

I know that this has been a hot topic in the past, and that there are a 
number of views about the overall suitability of RADIUS, which billing 
methodology is best, what is the meaning of life and such...

What I would like to know is has anyone found an open-source billing 
platform that performs basic billing functionality (pre/post) from 
RADIUS and/or Asterisk CDR and is written (well-written) in either PHP 
or PERL.

I'm hoping that others' experience can save me some time.