Have them communicate by a very simple protocol. I use YAML.

We already built the "administrative core" for a previous project. It uses an XML protocol, which is as complex as necessary to carry all needed tasks, unfortunately :)

You can write a library to talk to your privileged server. It's awesome.

Yes, and I even plan to make it possible (and easy) to create interface modules in Python,Ruby or dog forbid, PHP! :)

For the web app, I'm using Catalyst for the 1st time, and it's really as good as they say. Use it and kick yourself for anything web you've done that wasn't Catalyst. It's so easy to add a feature here or there. You never really know what you're building until you've built it, so being able to add stuff along the way is huge.

I never managed to wrap my head around these frameworks... I don't know.

I think I'm babbling... anyway, hope that's helpful.

Thank you.