PNL filename extension is associated with TopSolid, an advanced CAD/CAM modeling software. TopSolid was developed by Missler Software for Microsoft Windows system.

PNL files are used by TopSolid for storing nesting process data. PNL is a module file that offers functions to reduce material losses during production process. Nesting can be used for processing 2D or 3D models, as well as in 3D printing.