Creating commercial/closed-source apps using Openfire?

I am aware Openfire is under full GPL, though I don’t know GPL too well my assumption is that this means it would be very difficult to release a closed-source product which makes any use of Openfire code. Is that correct and are there known exceptions? For instance my understanding is GPL is restrictive enough that even bespoke plugins are ‘trapped’ by the license.

I’m leaning towards thinking I won’t be able to ‘escape’ GPL, but I thought I saw mention of alternative licensing for commercial projects. However I can’t see any details?