File => Import
Project Editor - File Menu - Geometry Project Only
File => Import => Packed Project
Selecting File => Import => Packed Project opens a browse window which allows you to select an archive file (.zon) then opens the Pack Project dialog box which allows you to unpack an archive file for editing.
File => Import => DXF
Selecting File => Import => DXF accesses the DXF translator to convert a GDSII format input file into a Sonnet geometry project file.
File => Import => GDSII
Selecting File => Import => GDSII accesses the GDSII translator to convert a GDSII format input file into a Sonnet geometry project file.