Hosting spots on Apache Servers
There are two different ways to get Apache to handle the 3DML MIME type correctly. Either upload a .htaccess file to the toplevel of your directory, or get your ISP to support the 3DML MIME type on the entire system.

You can put a .htaccess file in your top level Web site directory which will tell your Web server about the 3DML MIME type.

or

You can ask your ISP [Internet Service Provider] to add the 3DML MIME to the server directly. Flatland has created an automated request form-letter that makes asking your ISP a simple one-click task.