Files with the .fdm extension are data files created by Microsoft Exchange Forms Designer. This program makes forms to collect data. Users fill out these forms. To open an .fdm file install Microsoft Exchange Forms Designer. If it is already installed, update it. Updated versions support more file types.
You can also use Microsoft Exchange Server to open .fdm files. These files work on Windows. Other programs may support .fdm files too. The .fdm file contains the form’s design. This merges with HTML when the form displays. People use these forms to gather data from questionnaires, surveys, etc.