No. At this time, Respondus is a Windows-only product.
The University of Wisconsin-Madison offers an online Desire2Learn Question Import Tool. It is offered as a convenience for Macintosh users, and is not officially support by RIT. As long as you have Adobe Flash installed, you should see the Install Now button at the center of the page. There is an installation note right above the button. A link to their documentation discussing the formatting requirements is at the end of the second paragraph.