Sending Outlook meeting requests without Outlook?

I just wonder if it is possible to send Meeting Requests to people without having Outlook installed on the Server and using COM Interop (which I want to avoid on a server at all costs).

We have Exchange 2003 in a Windows 2003 Domain and all users are domain Users. I guess I can send 'round iCal/vCal or something, but I wonder if there is a proper standard way to send Meeting Requests through Exchange without Outlook?

This is C#/.net if it matters.