content: I wonder the same thing after getting deep into Linux and a career with it. Its clearly the better system but my understanding is its an unknown to many as well as they are entrenched with Microsoft. Whether it be .NET and/or ASP.NET apps, using IIS for whatever reason, an existing Exchange and Outlook infaststructure, etc or any number of things that they may be using causing lock in. At the very least businesses are going to continue having at least a couple Windows Servers for WSUS and Exchange for the foreseeable future. Things are slowly changing though.