Socialisme ou Barbarie (SoB) - France, 1948-1965
aka Socialism or Barbarism
SoB was a libertarian socialist group which had broken from Leninism following World War II. Strongly influencing the British group Solidarity, it argued that the bureaucracy which governed capitalism was the main enemy of society.
Key members: Cornelius Castoriadis/Paul Cardan, Guy Debord
Subsequent groups: Situationist International
Links on libcom.org
The Socialisme ou Barbarie archive
SoB search results on libcom.org [It could be worth searching for the English name also]