mozilla/addon-sdk — pull request #489 by wbamberg (2012-07-13 16:32:30+00:00)
Title: Bug 734201 - Tutorial for interaction with page scripts through page mod. 

I've documented how to use custom DOM events to communicate with page scripts, and expanded the window.postMessage documentation to cover both directions.

I've also split the old "content script access" page, which I always thought was a bit obscure, into 2 pages: "accessing the DOM" and "communicating with other scripts" which includes communicating with main.js, with other content scripts and with page scripts.