since we talked about setting the MIME type with PHP, we figured we might as well give an example of how to do it with classic ASP as well.

Serving XML:

Response.ContentType = "text/html"
Response.Charset = "utf-8"

Serving XHTML:

If InStr(Request.ServerVariables("HTTP_ACCEPT"), "application/xhtml+xml") > 0 Then
Response.ContentType = "application/xhtml+xml"
Else
Response.ContentType = "text/html"
End If
Response.Charset = "utf-8"

→ more information on serving XHTML