Communism

A few corrections:

1. For Marx, worker ownership is not Socialist. Cooperatives are petite bourgeois structures, the form of ownership must be public ownership, ie equal ownership across all of society, not just the working unit. Countries like Cuba, the PRC, and former USSR all have public ownership as the principle basis of society.

2. Marx had a decent idea of how Socialism would function, you can read a bit about it in Critique of the Gotha Programme. Lenin and other Marxists took the basis created by Marx and implemented the first major steps towards Communism in real life.