The open source VMware-sponsored Cloud Foundry Platform-as-a-Service (PaaS) project has introduced the new Cloud Foundry Core framework in a bid to try and address cloud PaaS interoperability.

NOTE: The Apache 2.0 licensed Cloud Foundry is primarily written in Ruby. It is described as an open Platform-as-a-Service providing a choice of clouds, developer frameworks, and application services.

The Cloud Foundry Core framework aims to give developers an opportunity to build applications that will be portable across PaaS-based clouds. It provides a baseline of common capabilities and an open mechanism to instantly validate application portability.

According to the site's official blog page, "Cloud Foundry Core defines specific versions for application services and runtimes and introduces a system of current, next, and deprecated to provide access to feature innovation, enhanced performance, and greater stability as applications continue to evolve."

AppFog, Tier3, Uhuru Software, Micro Cloud Foundry and Cloud Foundry.com are all now compatible with the Cloud Foundry Core framework. With the new Core offering developers have the option to enter an API endpoint to check for Cloud Foundry Core compatibility here.

Common capabilities are based upon the Cloud Foundry Core Definition (CFCD). The Cloud Foundry Core Definition (CFCD) is a baseline of common capabilities for the components of a PaaS offering that applications depend on. These capabilities include runtimes and services that are built with open development frameworks and technologies (Java, Ruby, Node.js, MongoDB, MySQL, PostgreSQL, RabbitMQ, Redis).