Communism was popularized by Karl Marx and Friedrich Engels. They wrote the famous political treatise called "The Communist Manifesto," which outlined the principles of communism as an alternative to capitalism. Marx and Engels believed that capitalism was inherently exploitative and unfair to workers, who were forced to sell their labor to capitalists in exchange for wages. They argued that communism would create a classless society in which the means of production were collectively owned and controlled by the people, rather than by private capitalists. According to Marx and Engels, communism would eliminate the exploitation of workers, create a more equal distribution of wealth, and lead to a more just and humane society. While communism has been implemented in various forms in different countries throughout history, its popularity has waxed and waned, and it remains a controversial and debated political ideology.