Here I would like to make distinction between the use of “socialism” as applied to States (i.e., the governments of countries) and as applied to, what today are called, “intentional communities.” I believe that Marx and Engels referred to speculation about such communities as “utopian socialism.” That is an unfortunate phrase because it suggests that these communities saw themselves as living in the best of all possible communities — which I don’t think they did. They simply thought this was a better way to live for them.
Anyway, there are three early books about these communities. They are:
The earliest of these books is by Noyes, and it is about types of communities as “socialisms.” And he distinguishes two types of socialistic communities: communistic and joint-stock communities. (Joint-stock communities are what Richard Wolff refers to as “worker-owned enterprises.”)
It is interesting to note which communities succeeded and which failed. To find out, read at least one of the books!
What Marx and Engels call “scientific socialism” has nothing to do with communal societies, but is rather a phrase equivalent to “social science,” which includes sociology, economics, and political study. But, in short, it is a critique of capitalism.
“Socialism” nowadays is used to refer to State interference with “laissez-faire capitalism.” Because the term “capitalism” is used in the sense that an individual should be free to trade with anyone for anything, “socialism” is seen as a constraint on this freedom. And this constraint can take the form of a government either taking over production, restraining and regulating trade and ownership, or providing welfare. From this perspective, a State is socialistic if it takes over the industries (nationalizes them), if it regulates production and distribution, and if it provides for people such things as old age pensions, free health care, free food, or free anything.
The most pernicious form of socialism to capitalism is a State which gives a free access to subsistence land. The reason this is so pernicious is that such a measure deprives capitalists (i.e. people with money to invest) from obtaining cheap laborers or even laborers at all.