13. Karl Marx
Marxist Internet Archive - https://www.marxists.org. Invaluable resource that includes key texts from Marx and hundreds of other Marxist and non-Marxist thinkers, plus biographies of thinkers and activists and a glossary of concepts and events.
International Institute of Social History Marx-Engels-Gesamtausgabe – https://iisg.amsterdam/en/research/publications/book-series/marx-engels-gesamtausgabe. Information on MEGA2: the ongoing project to publish the complete works of Marx and Engels.
Marx & Philosophy Society – https://marxandphilosophy.org.uk/society/. Society dedicated to Marx’s work, founded in the UK in 2003, which also runs the very useful Marx & Philosophy Review of Books.
Historical Materialism – http://www.historicalmaterialism.org/. Website of a leading Marxist journal, including reading lists, interviews, and book reviews.