I'm interested to hear feedback from a guru out there. If you are a java programmer, I'm sure you are familiar with openfire, while erlang programmers are familiar with ejabber. Which project has bigger community when doing programming in XMPP?
Here is an interesting case study from Chesspark, one of the larger XMPP sites out there:
Choosing An XMPP Server
They ultimately chose ejabberd, but you can read all about their decision processes.
It all depends on what type of development you do. If you are writing bots, clients or components, it's not very important. Choose the one you are the most comfortable with.
And you'll want to test for interop with other servers.
As for the community, you can always join one of xmpp.org mailing list, [email protected] being the obvious choice for the developer.
I do find that ejabberd's community is nice and reactive. (I, however, have a bias toward erlang and ejabberd ).
You might want to check out Tigase, a java xmpp server with the momentum OpenFire has lost.