Existed - and worked quite well, as a matter of fact - in Spain during the Spanish Civil War. In the midst of fighting, peasants and workers seized and socialized farms and factories, which became self-managed. Production rose above levels achieved under Capitalism and schools and roads were built. Hundreds of examples of innovations made by the workers and peasants are available, completely shredding the idea that socialism stifles progress. Unfortunately, Franco, with aid of Hitler and Mussolini, crushed the Republic and established a dictatorship.