Introduction.- Part 1 Foil Theories.- Optimal Information Transfer and Real-Vector-Space Quantum Theory (William K. Wootters).- Almost quantum theory (Benjamin Schumacher, Michael D. Westmoreland).- Quasi-quantization: classical statistical theories with an epistemic restriction (Robert W. Spekkens).-Part 2 Axiomatizations.- Information-theoretic postulates for quantum theory (Markus P. M?ller, Llu?s Masanes).- Quantum from principles (Giulio Chiribella,...