Shortly after the release of Firefox 22.0, Mozilla began offering the installer as a stub to download instead of the actual setup file. This allows Mozilla to use more logic before serving up an installer and hopefully saving them bandwidth as a result. The stub file for this version is called ‘Firefox Setup Stub 22.0.exe’ and is 274 KB in size.
When you hover over the normal download button at mozilla.org, you may notice that the URL has a parameter saying product=firefox-stub now: https://download.mozilla.org/?product=firefox-stub&os=win&lang=en-US
If you customize Firefox before deployment to your organization, you will probably need the full installer. Fortunately, that is still available for download under the Systems and Languages page where you can choose your language and operating system. Here the URL to the download shows: http://download.mozilla.org/?product=firefox-22.0&os=win&lang=en-US
Upon launching the downloaded stub file, a program will run with a few different screens. The initial screen allows you to check if you want Firefox to be your default browser, see other options, install, or cancel.
If you click the Options button, you will have the option to choose where Firefox creates shortcuts and where it gets installed along with sending install info back to Mozilla and another chance to set the default browser.
Once you click the Install button, the screen will switch to begin downloading the actual installer.
When it begins connecting, the screen will switch to another splash screen talking about the community of users, contributors, and developers.
Finally, as the stub gets to the Install process, you will get a haiku about Mozilla.
Upon the installation process completing, Firefox will launch.
While running the installer for one client, I received a notice saying that the download was interrupted but everything seemed to install just fine. If that’s any indication, the stub installer might still have some issues. Beyond the customization issue, the problem with stub installers is that they are useless to any technicians that might need to use them offline while taking longer to install the software on multiple computers because it needs to be downloaded each time. However, I guess it will always grab the latest version when it is run and can get online. Installers to reside on a USB key or server share will probably want to grab the full installer of the latest version from the Firefox All Systems and Languages page.