I've discovered a potential treasure horde tucked away in the deep dark folds of the world wide web. A 1625 page mammoth on all aspects of quantum field theory by Prof. Hagen Kleinert. There's a draft ed. for free available here - http://users.physik.fu-berlin.de/~kleinert/kleiner_reb6/psfiles/index.html I was looking for stuff to read on the Unruh effect (just for fun), after unsuccessful attempts to find mention of it in the usual qft books. I then came across Kleinert's book. And I unassumingly scrolled to the table of contents. And i scrolled and i scrolled, imparting as much angular momentum as I could to the mouse wheel. I think he's put everything in, from Higgs to excitonic insulators. I'm still learning the basics of QFT, so it'd be great if someone more conversant in the field could appraise this mammoth for me, especially the more advanced sections. I've looked at the first few chapters, and they seem well written. My background - I'm going through Schwartz with P&S as a supplement at the moment (I actually started with P&S last year, but found it too rough and decided to stop and learn GR first). I was planning to tackle Weinberg's QFT1 and Siegel's (mammoth) Fields next summer, but in light of papa mammoth's discovery, I'm rethinking my study program. Note that I don't intend to make my career on calculating scattering cross sections. I'm more interested in the conceptual basis of QFT, applications to many body physics etc.