Lately, I’ve had a few requests to build site-specific browsers (SSBs). SSBs provide some great advantages for companies that have web applications that simply work better on Firefox.

They can deliver their application to companies that don’t use Firefox. They can reduce support costs because the user can’t do anything to their browser that will break the application. They can ensure that their users are at a specific Firefox level. They can ensure that their users have any specific plugins or plugin versions needed for their application.

In the past, Mozilla had some technology around this like Prism and Chromeless, but decided that this avenue wasn’t worth pursuing. There is currently some work around building a web application runtime that will hopefully make this easier, but in the meantime, I’ve chosen to build my SSBs using XULRunner.

XULRunner is a runtime provided by Mozilla that allows developers to create rich applications like work just like Firefox and Thunderbird. Lots of companies have used it to build some great applications.

If you’re using XULRunner or have thought about XULRunner, you should be aware that Mozilla has plans to terminate the XULRunner build and encourage developers to use Firefox as a runtime. See this discussion on mozilla.dev.platform.

I’ve done some testing and I don’t see this affecting any work I’m doing around SSBs because the “Firefox runtime” should provide the exact same functionality that XULRunner does. In addition, because SSBs do not connect to the external web, they are not updated as often and can safely stay on an older version of XULRunner if necessary.

Do you use any site-specific browsers or other XULRunner applications? Do you think this change by Mozilla will affect you?