Value-form
The Western Left academics are nowadays very happy to talk about "varieties of capitalism", but talking about "varieties of socialism" remains almost an absolute "no-no". Most Marxists continue to believe in "only one" (Marxian) socialism: either that, or nothing at all. "Either" a society or movement conforms to the true concept of socialism, "or" it does not; and if it does not, it "cannot be" socialism. However, precisely "because" there are many different Marxist beliefs about socialism, Marxists cannot agree among themselves whether Soviet-type societies were socialist, capitalist, or something else. Some countries meet with the moral expectations which Marxists have, and others do not.Originally Marx and Engels themselves had heckled the advocates of "true socialism", but later Friedrich Engels and Karl Kautsky promoted Marxist socialism as the one and true "scientific socialism" within the Socialist International. When he was 43 years old, Lenin stated: "The Marxist doctrine is omnipotent because it is true". Lenin's Communist International (a deliberate split with the social democrats) adopted Marxist socialism as its official political doctrine.
Anarcho-communism
An important difference between anarchist communism and Marxist communism is who the product of the worker's labor belongs to. Both ideologies believe that the product of labor does not belong to the capitalist due to it being produced by the worker and not the employer, however, there are slight differences between the opinions taken by anarchist communist Peter Kropotkin and Karl Marx. Marx stated that the product of the worker's labor belongs to the worker due to it being produced by the worker. In contrast, Kropotkin believed that the product of the worker's labor belongs to the community as a whole. Kropotkin argued that this was the case because the worker relied on the previous work of untold millions in to even begin his particular form of labor, and therefore, his work should belong to the community, since he benefited from the community.