The Communist Manifesto
The book does not talk about or predict how communism would be in the future. It is a mixture of both Marx and Engels' theories and opinions on society and politics. It also has their written ideas of how the capitalist society of their time would be replaced by dictatorship of the proletariat, and after that, communism. Especially by the abolition of private property and child labour and by making means of production common, strong progressive income tax and free education for all.