Hello,
Spybot-S&D does also support other browsers than IE. It can empty the browser´s cache and history and checks for bad cookies, start page and bookmarks. ActiveX isn´t supported by Firefox, so there is no need for protection there. Maybe in one of the coming versions there will be a bad download blocker for Firefox, but not at the moment.
In addition, Spybot-S&D contains the Resident TeaTimer which is completely browser independent.
Best regards
Sandra
Team Spybot