Maybe not worth much, but in the Mitel version, I have seen some Postgres and recently they have stated that they are going to use an IBM developed db.
Thier web proxy blade is pretty cool too. It allows access to other internal servers, beyond what proxypass does. If it wasn't for all my time hacking dhcp, I'd be using their multi subnet dhcp server option to provide host addresses in my network.
Being a strong supporter of SME. just want the devs to know what is happening elsewhere.