This is a bitmap image format used in the VisiQuest Khoros visualization software suite. VIFF can be used to store bitmaps that are made up of color zones. It can store up to 2–3 color maps, and it is used to analyze visual data in research software.
This format is a vector images file in the Sketch Drawing program, which serves to edit and create interface designs, applications and software shells. SK-files contain objects and layers which can be edited independently of each other.