The Duet 3 Mainboard is a next generation controller board that builds on Duet3D's experience in developing the most flexible 3d printer control solutions. It is the core of the Duet 3 family which provides control for a wide range of machines including 3d printers, CNCs, lasercutters and more.
Product page is here: https://www.duet3d.com/Duet3Mainboard6HC
Documentation is here: https://duet3d.dozuki.com/Wiki/Duet_3_Mainboard_6HC_Hardware_Overview
As always please discuss this on the Duet3d forum: https://forum.duet3d.com/