Clones of ZBrush

Wanted: ZBrush clone2 days on the list, still without a clone

What it must meet

Name ZBrush.
Declare to be its clone or replacement.
Open its files (.zpr, .ztl).
Look and feel like ZBrush when in use.

Other 3D & CAD apps

3ds Max AutoCAD Cinema 4D Civil 3D Fusion Inventor Maya Revit Rhino SketchUp SolidWorks Substance 3D Painter