Is there a gelatin made from non-animal sources?
No. The word gelatin refers to a specific protein (collagen). There are similar substitutes depending on the application, but none are identical:http://www.vegcooking.com/vegcooking-gelatinalt.asp
Agar agar is a common vegetarian substitute. Do not use kosher gelatin; it is usually made from fish.
Are you asking because you want to have vegetarian marshmellows? If so, there are vegan (no animal products used) marshmellows out there. Similarly, you can make Jell-O without gelatin, too.