What is the best way to support a project commercially?

Yes :) Please file a task here describing a problem, so "we" (you included) can discuss a solution.

You can also enjoy these to speedup onboarding:

https://we.phorge.it/book/contrib/article/feature_requests/

https://we.phorge.it/book/contrib/article/bug_reports/

Hire a PHP developer and appoint him to the project?

Yes :) please hire your trusted and local PHP developer.

So they can just hack their local Phorge, and propose a git patch.

Hire someone from active community developers?

I think we are all employees. I personally only accept local pizza and only for very small jobs quantifiable in 2 pizzas.

But if you want to speedup my volunteer contributions, feel free to donate an incredible amount of money to Italian Linux Society (https://www.ils.org/info/#donazioni) so PayPal direttore@linux.it with subject "VALERIO PLEASE WORK ON PHORGE PLZ STOP DOING OTHER UNUSEFUL PHINGS"

Pay for hosting/tools/etc?

We had this interesting discussion in the chat Z1 and it seems our ship is very cheap and we can sail for adventure forever even without money. So we don't accept money or we could become an armed belligerent ship with laser cannons, and having lasers could be a problem for competitors.

Thank you for asking!

Yeah, this is a bit harder then it should be.

Our actual cash expenses are low enough that we're not concerned about them - I think it's somewhere around $100/year (For hosting + domain).

Possibly, the best way to contribute is by hiring a developer to work on your team's Phorge instance, and encourage them to get involved in the upstream's tasks. They will understand the system as a user/admin, and provide insights that arise from your use-cases, and they'll be able to work on upstream issues that actually impact them, in addition to having local patches/extensions that are not suitable to the upstream.

Hiring someone to work on Phorge is a proven avenue that worked well for the Wikimedia Foundation. For 7 years I was employed at the Wikimedia Foundation where something like 20% of my time was dedicated to working on Phabricator. Much of that work was contributed back upstream to Phabricator and subsequently became part of Phorge. Even after I left, other Wikimedia folks have been quite active in Phorge development.

If this is something you would like to explore, I'm currently available for contract work. I suspect some other Phorge contributors might also be interested in such an opportunity.

Since Phorge is very modular it is possible to develop features outside of the Phorge upstream but I would prefer to discuss the design with all Phorge contributors to ensure that it can be integrated in a way that is beneficial to everyone. At the very least to avoid any disruption.

If there is a particular feature that you would like to to sponsor then we could create a new Maniphest task to discuss it further.