"In late 1997 a leading French publishing house, Robert Laffont, published Le Livre Noir du Communisme (The Black Book of Communism), an 850-page book of scholarly essays that collectively provide a history of Communism in the 20th century. The contributors to the book include some of the finest scholars from both East and West, who have drawn extensively on new archival findings. Every country that lived (or is still living) under Communism -- the Soviet Union, the East European countries, China, Vietnam, North Korea, Cambodia, Laos, Cuba, Mongolia, and so forth -- is covered. The book also features many crucial, previously unpublished documents from the former Communist archives. "
I have not tried to read it on-line and I have not tried to download a copy but there are sites that make the text available. Our county library has it. I believe that French communists themselves produced the original.