@NicolaIsotta thanks for updating this. I assume you tested it and it worked as expected?

Yes. But I found an improvement I can make, I'll mark this as draft meanwhile.

Current behavior with NB 25 and primefaces 15:

With the PR, primefaces 15:

With the PR, primefaces 13 (which doesn't support the new namespace):

I added OmniFaces too, it has a URN taglib starting from version 5:
https://balusc.omnifaces.org/2024/11/omnifaces-50-m1-46-3147-2727-have-been.html

@NicolaIsotta thank you for your contribution. I updated the PR description with the images from the later comments.

@NicolaIsotta congrats on your first contribution btw!

Thanks for your efforts !
Quoting BalusC : you have during OmniFaces 5.x the opportunity to migrate the older XML namespaces xmlns:o="http://omnifaces.org/tags"
and xmlns:of="http://omnifaces.org/functions" to the single new XML namespace xmlns:o="omnifaces".
Yes, the both old namespaces of OmniFaces tags and EL functions have been merged into a single namespace for sake of simplicity.
I have tested it, but I still need the xmlns:of=http://omnifaces.org/functions if I use a function in my view .
Kind regards !
Louis

There's no need to add omnifaces functions namespace, it already works out-of-the-box in netbeans 26: