I review the existing framework of AdS/CFT correspondence for N=4 SYM. Then I discuss several possible ways to make the boundary theory closer to physical reality. I consider introduction of fundamental fermions, breaking of conformal symmetry and of supersymmetries. I revisit the geometric models (D3/D7, D4/D6, Sakai-Sugimoto), and "phenomenological models" (hard- and soft-wall), pointing out advantages and disadvantages of those. Finally, I speak on AdS/CFT in external fields and present my own new results in the area concerning quark condensate.
