Licencing
Mozilla and Firefox are registered trademarks of Mozilla.
While Mozilla hold copyright over these names and any associated logos, the actual source code for the Firefox browser is available under an Open source licence known as MPL.
A Community Edition is a version of Mozilla software that has some set of customizations beyond those normally allowed under the Mozilla Trademark Policy
Here is a link to the published version of the licence under which the Firefox source code is made available.
Community Editions of Firefox must adhere to strict guidelines to allow the use of the ther name Firefox Community Edition. While these are not official Mozillla builds, they do satisfy very strict provisions laid down by Mozilla.
