Year-end is as good a time as any to post a list from Lifehacker of some of the most popular Firefox extensions and themes of the past year. I installed Vacuum Places Improved and FireFound– check them out. Firefox extensions completely change the interface on your computer. I’d go so far as to say that for most users–most, not all–insofar as they are spending their time online rather than within applications on their desktop, the browser has become the operating system for all practical purposes. Why wouldn’t we take advantage of using as many extensions to it as we possibly can find?