Xeel

"Xeel" was the codename for a set of hardware-based navigational controls designed by Microsoft to create a simplified and consistent user experience for devices running the Windows operating system. "Xeel" was first demonstrated during Microsoft's WinHEC 2003, where it was characterized as a result of the synergy between hardware and software. Microsoft stated that its design goal for "Xeel" was to create a consistent experience for hardware devices that equaled the software interface consistency introduced by the mouse scroll wheel.