A status report is given on recent joint activities on the ITER CXRS and BES diagnostic package. Expected measurement performances are reviewed as well as comprehensive discussions are led on an integral approach to the implementation of Core and Edge CXRS observation periscopes. The “first mirror” location, its operational temperature, maintenance issues, and optimization of optical imaging are addressed. In parallel to more technical aspects, particular attention has also been given to the development of common evaluation and modeling tools. One part of this work is linked to the modeling of spectra for existing fusion devices and their CXRS diagnostics and extrapolation to the ITER environment. The purpose of this effort is to provide tools for the optimization of spectroscopic instrumentation, and moreover, the specifications of a suitable diagnostic beam.