Fraggles are not Muppets

I was talking to someone the other day about our favorite Muppets, and his was one of the Fraggles [wp].  I'm sorry but Fraggles are not Muppets.  Sure they were created by Jim Henson, but that doesn't make them Muppets.  Not to get all Mr. Continuity here, but the Fraggle's world and the world of the Muppets are separate and have never crossed over, unlike the Muppets and Sesame Street.