EVA is a platform, meant to be a standard for a printer to adapt in exchange for features that EVA brings with it's implementation.
The main feature is the compatibility layer between different hotends and extruders - EVA allows one to use E3D's V6, Slice's Mosquito and Copperhead, Dragon with any extruder from E3D's Titan. Bondtech's BMG and LGX, the Orbiter... and more options are added on every release. Aside from that EVA provides different bed probe and X endstop options.
Works with MGN12c and MGN12H.
EVA is open source and not controlled by any brand or company - only by the main author and the community.