dxu
There are 3 repositories under dxu topic.
ansonl/DXU
Improved and updated Dual Extrusion Upgrade (DXU) modification for Ultimaker. Get Marlin 2 DXU firmware at https://github.com/ansonl/Marlin-DXU
ansonl/Marlin-DXU
Marlin 2 for Ultimaker printers with DXU (UMO+/UM2/UM2+). See link below for latest repo.
ansonl/Marlin
Marlin firmware development repo and firmware customized for Ultimaker style printers