IRC

The Wesnoth-UMC-Dev project has its own IRC channel, #wesnoth-umc-dev at the Freenode network. There you can contact the admins in real time and ask for help, feedback, or just have a nice conversation with them. Just point your IRC client to #wesnoth-umc-dev @ irc.freenode.net [webchat | client] and you're ready to go!

Channel guidelines

Don't paste on IRC! Use the pastebin if you need to send more than two lines of code or error messages together in a conversation. Pasting directly on IRC annoys people and may even cause the IRC server to kill your connection.
Be polite, don't demand. We are humans, we have lives, and we are not always sitting at the computer ready to help you.
No 1337-2P33K or MESSAGES IN ALL CAPS, please. If you want to talk, do it in real English and politely. Using only upper-case letters on IRC, mailing lists or forum boards is globally understood as shouting. You don't shout all the time in real life, right?
Do not abuse the channel bots. Using them for your own leisure, by making lots of non-sensical requests, is not allowed and may get you silenced or banned.
Keep it on-topic. Although a certain degree of off-topicness is allowed when the channel is silent, it should be noted that reporting mainline bugs or writing feature proposals in this channel is pointless. Those should go to the #wesnoth or #wesnoth-dev channels (also at Freenode).

Tips

If you need to post an image and don't want to start a new thread or PM in the Wesnoth.org forums for that, you can use the Imagebin to upload your picture for enough time for us to see.
If you don't get a response within a minute or two, don't leave immediately or repeat your response. Although IRC allows people to talk in real time using text, one isn't necessarily close to the computer and/or keyboard all the time. Wait some more minutes (twenty is enough most of the time), and repeat your question. Half-admins and admins always read the logs and will notice your messages even when busy. Alternatively, you may send a private message with /query or /msg to a half-admin or admin and they'll reply as soon as they can.
If you want to ask something, don't ask whether you can ask or not! It's a waste of time and looks silly. Just ask your real question right away!