Currently Firefox users can go into the about:config and customize the preference browser.newtab.url to a specific web address (URL) or even set it to about:blank for a blank tab. However, so can malicious/unwanted software (McAfee, Ask, AVG, Babylon, Yahoo, etc.) by directly making changes the user’s prefs.js profile file. However, many novice Firefox users don’t know about or how to work within the about:config interface.

Mozilla’s solution to this as purposed in Bug 118285 (The browser.newtab.url preference is abused and should be removed) is to only allow (approved) add-ons to change the behavior of the new tab page. This would be landed in Firefox 41 which also coincides with new extension signing. The thought process on this is that it would be too much trouble for the makers of this software to create an add-on to override the user’s settings. Or if they did create an add-on Mozilla could easily blacklist said add-on.

I am not quite certain though what the (approved) add-on would change that can’t be manipulated through other means. From what I gather reading the bug is the changes would not be made in prefs.js, but rather some other file that can only be changed via the (approved) add-on.

Some people have issues with Mozilla going this route. Why should the user have to install an add-on just to change what happens when they open a new tab? This is especially true if the user can go into about:config and change browser.newtab.url preference. Well, as I mentioned in the beginning of this post not all users are familiar with about:config editor and also malicious software is making unauthorized changes to the users browser settings. Mozilla’s intent here isn’t to make it more difficult for users to change the way the new tab behaves, but prevent malicious software from making the changes in the first place. Thus making it so users wouldn’t need to change this setting at al.

There were a couple suggestions in the bug about changing the User Interface (UI) within the settings to allow users to control what happens when they open a new tab. Interestingly, neither Firefox nor Chrome allow you to change what happens when you open a new tab directly from the browser settings. Chrome has several extensions including Currently, that will change your new tab behavior. Safari sort of does in that it allows you to set new tabs to open your pre-set home page. The only browser that gives you the most control over what happens when you open a new tab (including the option to open a blank tab) is Internet Explorer (version 11 for sure).

This bug has already been landed into the Nightly builds of Firefox 41. We are still about 2 1/2 months away from the release of Firefox 41, so there is a chance this change could get backed out (but that is highly doubtful).