Short answers, pulled from the story.
The Coupled Model Intercombination Project began in 1995 under the World Climate Research Programme. A group called the Working Group on Coupled Modelling organized the effort to improve climate change knowledge.
CMIP2 emerged from a September 1996 meeting in Victoria, Canada where officials decided on inter-comparison of 1% per year compound increase integrations lasting 80 years. The Program for Climate Model Diagnosis and Intercomparison at Lawrence Livermore National Laboratory supports these phases by helping determine project scope.
First data for CMIP7 is expected end-2025 with a more continuous release approach announced for this latest iteration. Fast track experiments supporting specific requirements will be released continuously within this structure.
By 2018 CMIP6 had endorsed 23 Model Intercomparison Projects involving 33 modeling groups in 16 countries. This phase includes a common set of future scenarios comprising land use and emissions required for Shared Socioeconomic Pathways.
Climate model outputs enabled by CMIP3 helped prepare the IPCC Fourth Assessment Report released in 2005 and 2006. The IPCC Fifth Assessment Report summarizes information derived directly from CMIP5 experiments conducted between 2010 and 2014.