[gt384u]

For the sake of another data point, my own company provides a hosted PBX platform and just recently acquired another hosted PBX platform provider.

We are a hodgepodge of J2EE pre-SIPServlet on JBoss using Rhino for the scripting layer. Also, we acquired a company which essentially wrote their own Asterisk for Tomcat and built the current incarnation of our PBX platform on that. We do SBC with OpenSIPS and there are a number of other random bits and pieces (including Asterisk) which have played a role over the years. I have not seen the other company's codebase, but I am told they are a similar hodgepodge of PHP, Erlang (but not for the telephony bits), and possibly Java.

I would rather enjoy and appreciate any consistency in the platform, but I doubt we'll ever get to do the sort of rewrite that would provide that consistency.