There are three ways to get in communication with the Bugzilla developers: real-time chat rooms, Bugzilla, and the Developers Mailing List.
Real-Time Chat Rooms
The best way to contact the Bugzilla developers is through online chat. We have an official presence on three different chat services, which are all linked together, so you can join any one of them and everyone in all three places will be able to see what you post.
Feel free to drop into chat and ask questions. We all live in different time zones, though, so different developers are awake at different times. The channel may be a bit dead if it's currently night time in the United States and not yet morning in Europe, though usually somebody is there.
If you want to become a core Bugzilla developer, the absolute best way is just to hang out in chat for a long time. If you make it plain that you're a programmer and you want to work on Bugzilla, eventually somebody will just grab you and say, "Work on this!" Do be patient, though--that doesn't happen instantly.
What If Nobody Answers Me in Chat?
If you come into the chat room to ask a question, and nobody answers, just wait a while, or come in again at a different time! We're not ignoring you, we're just not there! We always answer people's questions, when we're around.
How to Connect to Chat
You can connect to chat in any of these places:
If you have a question about a particular bug, or some feedback on it, the best thing to do is to comment on that bug itself. We use bugzilla.mozilla.org for tracking Bugzilla development.
However, if nobody answers your question for a long time (after several days), come into IRC and ask.
If you want to make a broad announcement to all Bugzilla developers, you should use the developers mailing list. Bugzilla developers call this mailing list "developers@" for short.
If you're going to be a Bugzilla developer, you should definitely be on this list. It isn't a high-volume list, although once in a while we do have long discussions on the list.
However, if you just have a simple question to ask, don't use the list, use the chat rooms.