Open Source Portal
A lot of the documentation below is geared toward developers. However, many aspects of the system don't require a deep technical background to learn. Much of this is still a work in progress, but since this is a wiki, you can help fill in the blanks!
We want your help to make the Second Life Viewer better! You don't need to know C++ or even programming to help. Some of the toughest jobs in software development have nothing to do with writing code. Just grab a test build and try playing around with it. Let us know what you think on email, on the forum, or IRC. 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. If you run into issues, see if a bug report has been filed, and if it isn't file it. If it has been filed, vote for it, perhaps filling in more detail.
Of course, if you are a developer, we can use your help. Download the code, and see if you can get it to build. Try your hand at fixing a bug, or extending the software through one of the APIs. There's a ton of ways you can help, and we welcome you regardless of your skill level.