This is a torrent I've been seeding for a while, it's pretty good.

Torrent description:

A collection of books that pertain to socialist/worker's-movement theory, history, movements or figures, with a focus on more recent works that aren't often available on public-domain archives. Not every book is explicitly socialist in outlook; there are a handful of books in here that just relate to important developments in history that might be interesting to a socialist (for example, King Leopold's Ghost, a study of the horrors of Belgian colonialism in the Congo Free State, or Judith Butler's Undoing Gender.)

A mixed bag of formats; EPUB and MOBI when possible, PDF otherwise, with some HTML, TXT and DOC mixed in when totally unavoidable.