[Excavator]

You can use Profiles¹ for that sort of stuff. about:config² is good for a somewhat complete list of components that can be enabled/disabled.

1: https://support.mozilla.org/en-US/kb/profile-manager-create-...

2: about:config?filter=.enabled

[canuckistani]

See also the profilist extension:

* https://addons.mozilla.org/en-US/firefox/addon/profilist