What does Firefox add to XULRunner?

Question

Firefox - XULRunner = What?

Details...

Another way of putting this question is, what does the 'firefox app' consist of (besides the XULRunner portion of code)?

Answer 1

This is the answer I got from firefox mailing list.

You're missing the entire browser frontend. Firefox is everything in the browser/ directory of the source tree

http://mxr.mozilla.org/mozilla-central/source/browser/

including the following:

• The UI of the main browser window.
• UI of the preferences window
• Feed handling UI
• Data migration for new users
• UI for the bookmarks/history data
• Session restore
• Shell integration

There's a lot that goes into Firefox beyond the web platform that XULRunner provides!

--BDS

Answer 2

Beyond the UI written in XUL, I imagine the answer would include the rendering engine (Mozilla), the javascript engine (Tracemonkey, Jaegermonkey, etc), security and encryption, networking (http, https, ftp, etc), bookmarking and history....

Many of these things would be in discrete libraries, meaning that the main app itself is really just the glue that hold them all together, but they are there nevertheless and all important parts of Firefox as an application.

Answer 3

Firefox adds the user interface, provides at least some of the add-on system and makes it something that can be used as a web browser by a user. XULRunner is just a platform to run XUL apps on, whether it be Firefox or Thunderbird or Songbird or something else.