The library is a storage of custom presets for specialized tools in LwCad.
You can add your custom shapes into library using Add to Lib tool.
The library has the following basic types:
Window: a polygonal window object with a defined drill shape
Door: a polygonal window object with a defined drill shape
Fence: a polygonal fence object
Column: a polygonal column object
Element: a polygonal element object
Shingle: a polygonal shingle object