The World Socialist Movement (WSM) is an international organisation of socialist parties created in 1904 with the founding of the Socialist Party of Great Britain. The member parties share a common classical Marxist worldview and an adherence to socialism defined as a distinct economic system from capitalism. As a result, the parties of the World Socialist Movement are held in sharp contrast to social democratic political parties and Marxist–Leninist movements. In contrast to social democratic parties, the World Socialist parties do not pursue social and economic reforms to capitalism, nor do they seek political office in electoral politics, and they do not focus on "progressive" causes, believing such actions to be irrelevant to their fundamental goal of socialism. In contrast to Marxist–Leninist Communist parties, they do not subscribe to the theories of imperialism, vanguardism and democratic centralism, believing such practices to be antithetical to the realisation of socialism.
The World Socialist Party of the United States (WSPUS) defines socialism as a moneyless society based on common ownership of the means of production, production for use, and social relations based on cooperative and democratic associations as opposed to bureaucratic hierarchies. Additionally, the WSPUS includes statelessness, classlessness and the abolition of wage labor as characteristics of a socialist society—characteristics that are usually reserved to describe a communist society.