Mozilla relies on Linux Cross-Reference (or LXR for short) in order to navigate, link to, and generally communicate with one another about the source tree. You can access Mozilla's LXR at http://lxr.mozilla.org. As a developer working on Mozilla projects, learning to use lxr effectively is essential.
List of Topics to Investigate
Pick one of the activities from the list below (do more than 1 if you finish early), or add your own if you have one applicable to your project.
Create a link out of the title and document what you find with lxr links and description in that page.