GT Common Runtime Components (Core, XIO)
Although these components were first introduced in GT3, the term "common runtime components" has been used beginning with GT4 to describe these components that provide web and pre-web services with a set of libraries and tools that allows these services to be platform independent, to build on various abstraction layers (threading, io) and to leverage functionality lower in the web services stack (for GT4: WSRF, WSN, etc).
These components are architecturally diverse and it is thus hard to identify a overarching theme. Instead a few sub-themes have been identified and elaborated on in the GT 4.0 Common Runtime Component Key Concepts.
The following links provide consolidated information (links to downloads, docs, related software, etc) about the following components:
In addition, GT4 provides Python WS Core as a contribution.