Preheat the oven to 400 degrees F. Butter 8 (1/2 cup) ramekins or gratin dishes. In a large bowl gently combine the plums, raspberries, flour and sugar. Distribute this mixture evenly among the ramekins. In a separate bowl, combine the pecans, flour, brown sugar, melted butter and salt. Divide this mixture evenly among the ramekins. Place the ramekins on a cookie sheet and place in the oven for 20 minutes, or until the topping is golden brown.