GNU LibreDWG is a C library to handle DWG files.  It aims to be a free
replacement for the OpenDWG libraries.  DWG is the native file format
of AutoCAD.

LibreDWG was based on LibDWG (http://libdwg.sourceforge.net), which is
written with variable names, documentation, and comments in Esperanto.

There are also command line tools and libraries to read and write DWG
files, with converters for various formats (DXF, DXFB, SVG, PS, JSON,
XML, etc.) and a SaveAs functionality, to convert between the various
DWG versions.  It can read r13-r2018 DWG, write r13-r2000 DWG, write
r11-r2018 DXF ASCII and binary.  Much more object types than any other
free DWG library.

WWW: https://www.gnu.org/software/libredwg/