The Global Model Exchange (GME) Grid Service is a simple, stateless service, created with [Introduce|introduce:Home], which acts as an authoritative XML Schema registry for the grid. It's primary function is to ensure global referential integrity of all the XML Schemas used on the grid, and provide operations for their registration and discovery. It provides utility APIs for uploading from and downloading to a local file system, graphical interfaces, and integration into [Introduce|introduce:Home] as a data type discovery mechanism.