Secondary profiles allow you to have another complete set of settings (bookmarks, emails, calendars, preferences, etc) for each portable app. It's great for sharing your flash drive with someone else, development and testing extensions or separating work/school stuff and personal stuff. The secondary launchers work with all versions and all languages and are available from the portable apps' support pages today.

A second profile can allows you to setup another set of settings (bookmarks, extensions, preferences, etc) for Firefox Portable that you can use independent of your main settings. This is useful for sharing a flash drive with someone, testing extensions and configuration options or separating our work from personal details.

To use a second profile, install the Firefox Portable 2nd Profile 1.0 app in the same PortableApps directory that FirefoxPortable is in (so, if Firefox Portable is installed to X:\PortableApps\FirefoxPortable, you'd install this to X:\PortableApps\FirefoxPortable2ndProfile).

In the PortableApps.com Menu(!), it will show up as "Mozilla Firefox, Portable Edition 2nd Profile". You can easily rename it to something more useful by right-clicking and selecting rename. When you run it, it will start Firefox Portable up with your second profile without affecting your main profile. You can even install a 3rd or 4th profile by installing the 2nd Profile app again to another location (like X:\PortableApps\FirefoxPortable3rdProfile) and then renaming it in the PortableApps.com Menu.

Note that only one profile can be used at a time, even with MultipleInstances turned on in the advanced launcher INI. This is a limitation of Firefox itself.