The EU project Metafor has elaborated for CMIP5 a framework for describing essential elements of the coupled models involved, and of the experiments. This is called the Common Information Model. Basic informations are available on the CIM site; However, for a number of ancilliary files, and initial and boundary conditions files, the CIM site only provide URLs to documents and files handled by each institution contributing to CMIP5.
At a later stage, you will find here a number of topical articles providing the relevant data
Describes CNRM-CM5 boundary conditions files