Is there an Alpha or Beta version of Grasshopper for the Mac? (or any other OS)

No.

Really, no.

A serious effect is being made by McNeel to provide the RhinoCommon SDK for iRhino using the Mono framework. Some progress has already been made and we're pretty confident about it, but at the moment all effort of the McNeel Seattle HQs is invested in Rhino5.

There are no plans to port Grasshopper to Operating Systems other than Windows and Mac Os, or indeed 3D applications other than Rhino.

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David Rutten

david@mcneel.com

Poprad, Slovakia