Catalyst 5.9 is coming up, and the big change is a wholesale switch to PSGI, completely dropping Catalyst’s own engine system (outside of compatibility shims). This is bound to bring in new people wondering what PSGI and Plack are all about and what you can do with them.

I’ve been using Catalyst on top of Plack for a while now (with the aid of Catalyst::Engine::PSGI) and have gotten around to some nifty things with it. So here is my app.psgi for inspiration: