I run Rasbian with X over HDMI and ran the default Mathematica install put get: In[3]:= p=Plot[Sin[x],{x,0,2 Pi}] Out[3]= -Graphics- In[4]:= Export["testplot.png",p] Developer`LaunchFrontEnd::nxsrv: An x server is required for that operation. Rasterize::nofe: A front end is not available; Rasterize ...