Developer communication tools
Let us know what you think on email, on the forum, or in-world. If it's not working for you, try to get help there. If it is working for you, try helping someone who isn't having as much luck as you are. File bugs - if you run into issues, look through the bug database and see if a bug has been filed. If so, vote for the issue to be fixed. If not, file the bug.
Mailing List
SLDev@lists.secondlife.com - mailing list for discussing the development of the Second Life viewer. This is a high-traffic mailing list (as many as 30-40 messages/day on a busy day). For a weekly summary of this mailing list, see SLDev Traffic. You may also want to search the SLDev archives.
Forum
If you are having issues getting things built, and you just want to ask a quick question, please ask it in one of the "Technical Talk" forums.
JIRA
Second Life JIRA, submit bug reports, reproductions and patches for issues relating to the open source viewer
Wiki
You're soaking in it...
This is the place to post documentation, more indepth discussions, and various projects
IRC
Internet Relay Chat - your instant way to communicate irc://irc.efnet.org/#opensl
Resident Run Groups
- Second Life Source Developers (Not a Official Group)
- OpenSL -- The OpenSL project at openmetaverse.org
In-World
The Hippotropolis region is a gathering place for developers and residents interested in improving the Second Life Viewer. Teleport to the Linden Open Source Project headquarters.