Marxists Internet Archive, also known as MIA or Marxists.org, is a non-profit online encyclopedia that hosts a multilingual library (created in 1990) of the works of communist, anarchist, and socialist writers, such as Karl Marx, Friedrich Engels, Vladimir Lenin, Leon Trotsky, Joseph Stalin, Mao Zedong, Rosa Luxemburg, Mikhail Bakunin, Peter Kropotkin, and Pierre-Joseph Proudhon, as well as that of writers of related ideologies, and even unrelated ones (for instance, Sun Tzu).

a Santa Cruz, California-based website dedicated to the preservation of electronic public domain religious texts.