Kieron Burke has written a very readable perspective on density functional theory in Journal of Chemical Physics, who, very commendably, has made it freely accessible.
To whet your appetite here are some quotes from the paper:
If you enjoyed the article you may also want to check out this presentation of Kieron's entitled "Density Functional Theory: A great physics success story"
If you wish to annoy and confuse a traditional quantum chemist, ask “How much correlation is there in the KS wavefunction?”
When teaching chemistry students, I explain that DFT is some algorithm meaning unreliable, while ab initio is Latin for too expensive.
Interestingly, I have recently co-authored an approximation with about 105 “empirical” parameters.111 Don Truhlar, eat your heart out!
Users should stick to the standard functionals (as most do, according to Fig. 1), or explain very carefully why not.
Thanks to Sten Rettrup for alerting me this paper