Extension creation main steps (as a folder)

1-create the file chrome.manifest at the top of your extension's folder (with the values , overlays)

2-create the file install.rdf at the top of your extension's folder (with the values, information about the extension)

3-Locate your default profile folder.(C:\Documents and Settings\eyad\Application Data\Mozilla\Firefox\Profiles\mz8tjh1o.dev\extensions)

4- inside this directory create a file with the extension id as its name (e.g. iyad@iyad.net), then inside this file point where is the extension located in the harddisk (D:\FirstExtesnsion\helloworld\)

5- to add the javascript files add the file name in clc_utilsOverlay.xul

To package extension just zip the contents folder and rename the extension into xpi

NOTE: in FireVox the main file for mathML rules are clc_mathml_main.js located in clc-utils\chrome\content\clc_utils