1)   HPGL Export for Rhino 1.0
HPGL Export for Rhino is a HPGL plot file export plug-in for Rhino. This plug-in gives Rhino the ability to export geometric data from Rhino to HPGL Plot (PLT) files.

 2)   PLT Export for SolidWorks 1.0
PLT Export for SolidWorks is a HPGL Plot PLT file export add-in for SolidWorks®. This add-in gives SolidWorks the ability to export geometric data from a SolidWorks drawing document to a HPGL PLT file.