From Espresso to Codex
  CODEX and ESPRESSO are concepts for ultra-stable, high-resolution spectrographs at the E-ELT and VLT, respectively. Both instruments are well motivated by distinct sets of science drivers. However, ESPRESSO will also be a stepping stone towards CODEX both in a scientific as well as in a technical sense. Here we discuss this role of ESPRESSO with respect to one of the most exciting CODEX science cases, i.e. the dynamical determination of the cosmic expansion history. 
J. Liske, L. Pasquini, P. Bonifacio, F. Bouchy, R.F. Carswell, S.   Cristiani, M. Dessauges, S. D'Odorico, V. D'Odorico, A. ...