LIP6 and EDF have started to develop an RM-ODP framework for building open distributed systems. The first concern of this development was the construction of the Specification Exchange Service. This service, the so-called Backbone, enables to exchange RM-ODP specifications over any ORB or file system. This article presents the functionalities of the Backbone in the RM-ODP framework and its explains how meta-modeling standards such as MOF and XMI have been used to create it.