Linux is freely available, and no one is required to register their copies with any central authority, so it is difficult to know how many people use Linux. Several businesses are now surviving solely on selling and supporting Linux, and very few Linux users use those businesses, relatively speaking, and the Linux newsgroups are some of the most heavily read on the internet, so the number is likely in the hundreds of thousands, but hard numbers are hard to come by. However, one brave soul, Harald T. Alvestrand, has decided to try, and asks that if you use Linux, you send a message to linux-counter@uninett.no with one of the following subjects: ``I use Linux at home'', ``I use Linux at work'', or ``I use Linux at home and at work''. He is also counting votes of ``I don't use Linux'', for some reason. He posts his counts to comp.os.linux.misc.