It depends on who you listen to the most. In the botanical world, "stone fruit" is generally thought of as a less technical term for "drupe", a specific type of fruit. In which case, there are a lot of plants that produce stone fruit. Highbush cranberries, autumn olives, and true olives are three that come easily to mind, but there are many others.
In the culinary world, on the other hand, the term stone fruit tends to be applied mostly to plants in the Prunus genus.