Stencil Files:  For laser or chemical etch stencils.

CNC Drill Files:  Excellon, Sieb & Meier

HP-GL Files:  For use in penplotting, or CAD upload.

DXF Files:  CAD upload.

PCX Files: Used in publishing/documentation systems or archival.

Printer Plots: Lower resolution "check plots".

Placement Files: Files containing X,Y centroid, rotation and descriptive information. For use in most dispensing, insertion and SMD placement equipment.