All communists are at first socialists, after all. Marx only used the word "communist" in order to take on a more radical term, it was Lenin that used socialism as a descriptor for what Marx called the "lower stage of communism" just to help make things easier to understand. There really aren't any significant numbers of people that want to "freeze development" at socialism, among the two largest umbrellas for socialists are Marxists and Anarchists, and neither sees socialism as the final stage.