  The experience from Quantum Information has lead us to look at Quantum Theory
(QT) and the whole Physics from a different angle. The information-theoretical
paradigm---"It from Bit'---prophesied by John Archibald Wheeler is relentlessly
advancing. Recently it has been shown that QT is derivable from pure
informational principles. The possibility that there is only QT at the
foundations of Physics has been then considered, with space-time, Relativity,
quantization rules and Quantum Field Theory (QFT) emerging from a
quantum-information processing. The resulting theory is a discrete version of
QFT with automatic relativistic invariance, and without fields, Hamiltonian,
and quantization rules. In this paper I review some recent advances on these
lines. In particular: i) How space-time and relativistic covariance emerge from
the quantum computation; ii) The derivation of the Dirac equation as free
information flow, without imposing Lorentz covariance; iii) the
information-theoretical meaning of inertial mass and Planck constant; iv) An
observable consequence of the theory: a mass-dependent refraction index of
vacuum. I will then conclude with two possible routes to Quantum Gravity.
