They're a Microsoft shop in that they use Outlook, Word, Excel, etc. They don't have a bunch of .Net or SQL Server applications already built. It's simply their sense that because they use Microsoft products, a .Net site would be a better option.
The fact that they use MS Office doesn't mean their Web site should be developed in .Net any more than using Open Office would dictate use of PHP. I'm simply looking for some language to support using PHP over .Net.
Thanks.