For the first time their writings are being made fully available in English, including manuscripts not published during their lifetime, their correspondence as well as supplementary notes, outlines and projects. Fully annotated and with bibliographical data and indexes. The set will be 50 volumes.

Part of a definitive English-language edition, prepared in collaboration with the Institute of Marxism-Leninism in Moscow, which contains all the works of Marx and Engels, whether published in their lifetimes or since. The series includes their complete correspondence and newly discovered works.