Spring IO brings together the core open source Spring APIs into a cohesive and versioned foundational platform for modern applications and is comprised of the Spring IO Foundation and Spring IO Execution layers.
The Spring IO Platform, which is intended to increase developer productivity, integrates devops capabilities and enables new classes of applications, such as big data systems. Key components of Spring IO include Foundation, which features APIs and embeddable runtime components for building enterprise applications, and Execution, offering domain-specific runtimes (DSRs) for applications built on the IO Foundation. DSRs can stand alone without requiring deployment to an external container.
Sources: http://www.infoworld.com/t/java-programming/java-ee-tough-sell-spring-framework-users-226761