Does anyone have an idea of what the installed base of UNIX servers is? I'm especially interested in UNIX email servers. If anyone knows where I can go to get this sort of information, I'd really appreciate it. Thanks
Because UNIX is a design philosophy versus a product, there is little motivation for all the millions of UNIX users using FreeBSD, Linux, BSDI to report for marketing purposes. Any numbers for UNIX would be just a random guess and have little meaning.
Also, geography plays a role. Outside of the US, free UNIX plays a much greater role than in the US. I recall many conversations with savvy Europeans who don't understand why people in the US waste money on purchasing inferior NT servers when they could just install a very mature and robust UNIX-of-their-choice for almost free.
Think of this. I have more than 8 Linux servers running. What report would capture that? I don't report these to any registration authority. ISPs, businesses, telcos, home businesses, big business, research labs, defense departments (you name it) use a very large number of UNIX-type servers for mail hosts, web servers, name servers, application servers, etc. etc. etc.
It is impossible to have any meaningful number of the total UNIX server base in the world. I have 8 servers and no TV, so I have an infinate number of servers compared to my install TV base. The same goes for NT. I have zero NT server on my net and use Samba as a file server for my Windows clients.
A few years ago, a high ranking official told me he judged the install base by the number of books on the shelves in bookstores. At that time Windows dominated UNIX and Linux. I don't know about your area, but here UNIX (driven by Linux and Apache server) dominate Windows in shelf space.
Perhaps using the 'leading books store shelf space metric' would help you too