What we are reading here is an English translation of the Manifesto and Das Kapital, which was written in German. Engels attempted to translate the Manifesto into English, but gave up. The first translation of the Manifesto in English was by a Scottish Chartist Helen Mcfarlane in 1850. The first translation read,"A frightful hobgoblin stalks throughout Europe. We are haunted by a ghost, the ghost of Communism". Mcfarelane ultimately dropped out of politics, married a vicar, and died in the full embrace of the Anglican Church. It's funny how religion didn't go away in Russia either.
The Manifesto of the Communist Party languished in obscurity for 20 years. Anarchist Mikhail Bakunin pulished the first Russian version of the Manifesto in 1869 after making signicant alterations to it, and the first version published in Germany appeared the same year. The 1888 English version translated by English lawyer and colonial adminstrator Samuel Moore was approved by Engels (Marx died in 1883) and remains the standard translation, and I assume it is the one featured here.
Marx' writings were also responsible for Pol Pot and the killing fields, the sinister Derg in Ethiopia, the disaster that is Venezuala, the Cultural Revolution, the Iron Curtain, and all kinds of other horrors and evildoers.