As a general rule of thumb here: if it works in Firefox using a Windows OS,
it will work in Firefox in Linux. There are some specific "in browser"
aplications that require Active X to operate (such as remote to desktop
connections using Microsoft Live Mesh), and for that, you need to install
Internet Explored in linux, either under a Virtual Machine or using Wine
from the repositories. I haven't personally installed Int. Explorer yet,
but it is on my list of to-dos so I can connect to my company-owned work PC.