Enthusiast System Architecture

The Enthusiast System Architecture (ESA) specification is a royalty-free protocol for two-way communication of PC components.

The ESA USB specification was created by a joint venture between Microsoft, Nvidia, Logitech and several other companies.

[2] The protocol remains open and royalty-free; but, no manufacturers are currently utilizing its specification at this time.

The ESA specification is built around the current USB human interface device class specification and ESA was sent to the USB Implementers Forum HID subcommittee for discussion and approval in early 2007.

Only one software implementation exists; it is Nvidia's proprietary "System Tools with ESA Support" which only works on nForce-based motherboards and only runs on Windows.