The EU project Metafor (Metadata For Climate Modelling Digital Repositories) is developing a common information structure for describing complex climate models, their runtime technical and scientific context, and their data outputs. It is also building tools to help create, discover, view and manipulate the resulting metadata, helping scientists to make the most out of the huge volume of climate model data routinely produced. The project will leave a legacy of services deployed to maintain the infrastructure developed within the project. This presentation will introduce the main concepts defined by model metadata within Metafor (aka the Common Information Model or CIM), and how the CIM is building on other metadata initiatives both in Europe and worldwide - ranging from the exploitation of ISO standards, to support for the European spatial data infrastructure (INSPIRE) and the Global Earth Observation System of Systems (GEOSS). It will also outline how Metafor is contributing to the metadata requirements and collection of the forthcoming fifth Coupled Model Intercomparison Project (CMIP5) led by the World CLimate Research Programme (WCRP) in support of the next IPCC assessment.