Postgres on MacOS... Is it even a possibility?

Someone recently asked me about PostgreSQL as they were looking into
integrating some of the software they produce with a database system. I'm
not sure the specifics of the planned integration itself, but one of the
requirements they had was support for MacOS.

I was wondering if anyone has thought about MacOS support. Is it even
possible? Is there some great impediment to porting or is it just that
there is not enough need to justify the effort? The person that asked me
is actually one of the main C/C++ programmers at the company, (They are a
local development house that is owned by a very large software
publisher...no not Microsoft.) and he expressed some mild interest in
working on a port if it was feasible, so any input on this subject would be
appreciated as I might be able to convince him to work on it. :)

Thanks in advance!

-Jesse