Glyph's post on threads
Glyph Lefkowitz is a great author. In this post titled unyielding he makes an excellent case against threads, with so many valid references for his arguments. He makes a point event driven programs that should be the first thing we should think if we are think about concurrency.
As a developer or project lead, if I have to emulate certain practices for a writing high quality software, I think, looking up to glyph and his twisted project is never a mistake.