VMEBus Switched Serial, commonly known as VXS, is an ANSI standard that improves the performance of standard parallel VMEbus by enhancing it to support newer switched serial fabrics. The base specification defines all common elements of the standard, while "dot"-specifications define extensions which use specific serial fabrics or additional functionality. VXS is backward compatible with VMEBus. It is defined by the VME International Trade Association (VITA) working group.