Creating a Customized Firefox Distribution

You may have heard of the the Firefox Build Your Own Browser Project. On the web page, it says it “is a simple way that your organization can create and distribute a customized version of Firefox.” I think BYOB is a great start to solving the distribution problem, but it’s missing one key thing – the ability to bundle your own add-ons.

What I’m going to do with this post is explain exactly how BYOB works internally so that you can create your own distribution that has all the customizations you want. There are a some downsides to our method – primarily that we are Windows only and that we can’t sign our installers with the Mozilla certificate. But it’s the only way we can create a distribution that includes our own add-ons.

BYOB works by taking advantage of the features of the distribution directory in Firefox. The main component of the distribution directory is the distribution.ini file. The distribution.ini does have some documentation, but there are a few more tricks that we need to know about.

Previously I had talked about customizing the Firefox installer, and all that information is going to come into play here. What we’re going to do is after we’ve unpacked the Firefox installer we want to use, we’re going to create a subdirectory called distribution in the nonlocalized directory. In that directory, we’re going to create a file called distribution.ini. We can use this web page as a template for that file. The distribution.ini file is going to contain any preferences and bookmarks that we want to specify as part of our distribution. Information on how to create those things is in the sample file.

Next up are search engines. Search engines are placed in a subdirectory called searchplugins under the distribution directory. For search engines that we want installed for everyone, we put them in another subdirectory called common (searchplugins/common). If there are search plugins we want to be locale specific, we can put them in a directory that is named the same as the locale (This is all documented in the sample distribution.ini).

When I talked about customizing the Firefox installer, I indicated that you could preinstall add-ons by unzipping them into the nonlocalized/extensions directory. With the distribution directory, we have a new option. If we create a bundles directory and then put our add-ons in there, they are completely hidden from the user. They can’t be uninstalled or disabled. The method for putting add-ons in this directory is the same as before – create a directory that named the same as the ID of the add-on and then unzip the add-on into that directory.

If you’ve used BYOB, though, you may have noticed that they do things a little differently. If you bundle add-ons with your browser, they are installed the first time you start the browser. And if you create another profile, it gets those add-ons as well. And they are installed into your profile directory. This is accomplished is via a custom add-on that was created by Appcoast called the Addon Installer. I could find no information at all on this add-on. I’m going to document here how it works, but if you choose to use it, it’s at your own risk. To obtain it, you can download any of the browsers at the bottom of the BYOB page. After unpacking one of those installers, you’ll see the Addon Installer in nonlocalized/distribution/bundles/{04C927C9-E491-4DDC-9D45-54C145422A15}. Just duplicate that directory in your distribution. If I get a chance, I might create a version of this that is open source.

To use the Addon Installer, place the XPI files you want to install into a directory called extensions under the distribution directory. Then create a file called config.ini in that directory. The format of the config.ini file is like this:

[Extension0]
id=THE ID OF THE FIRST EXTENSION
file=THE XPI OF THE FIRST EXTENSION.XPI
Version=0.0.0
OS=ALL
[Extension1]
id=THE ID OF THE SECOND EXTENSION
file=THE XPI OF THE SECOND EXTENSION.XPI
Version=0.0.0
OS=ALL

Most of this is self explanatory. The only interesting part is OS. If for some reason, you need an add-on to be OS specific, put the OS name instead of ALL. You can see the OS names here.

Once we’ve made all these customizations, we can follow the instructions in my previous post to package our installer. Also, if you want your installer to say “Mozilla Firefox for Your Company”, don’t forget that you can do that using the setup.ini that is mentioned in that previous post. That’s in localized/distribution, NOT nonlocalized/distribution.

So in summary, while I usually plug the CCK Wizard, if all you need to do is set some default prefs, add some bookmarks, bundle some search engines and bundle some add-ons, the distribution method might be for you. If you need to do more detailed customizations, check out the CCK Wizard.

And as always, if you need help with any of this, you can contact Kaply Consulting.