Considerable interest is currently emerging in an economic system that would combine the basic socialist principle of public ownership of the non-human factors of production with the basic free market principle of relatively limited control over the economy by the central government. Such a system has come to be known as “market socialism.” This paper provides a survey over the four primary variants of market socialism that may be distinguished in the economic literature. These are as follows: 1) Langian socialism aims at a socialist equivalent to perfectly competitive capitalism; 2) service socialism aims at replacing profit maximization with constrained output or revenue maximization; 3) cooperative socialism aims at installing the employees of the enterprise as its “ultimate” managers; 4) pragmatic socialism aims at a socialist equivalent to contemporary real-world capitalism, whether this system is perfectly competitive or not. A brief description and discussion of each of these variants is provided, together with a review of the relevant literature. The article is concluded with an argument that of the four variants, the pragmatic is the most attractive in terms of possible real-world implementation both because its similarity to capitalism reduces the possibility of unfortunate deficiencies of theoretical blueprints as a guide to actual behavior, and because it best reflects those aspects of the traditional socialist ideal and intent that remain fully valid even at the present time.