LibreCAD is a free 2D CAD and geometry drawing application. Originally forked from the community version of QCad, LibreCAD has been under active development for improved CAD features, 2D geometry engine, and internationalization and localization. In the current stable release of LibreCAD, the code base has been updated from the original Qt3 to be based on boost, Qt4/5, and C++11.
The areas of LibreCAD development are largely based on user feedback, and active development has been observed in DXF support by the dxfrw library, DWG suppport (under development), conic curves support (under development), and other generic computational geometry features.
Operating systems supported by LibreCAD include Windows, OS/X, and unix-like, and support of mobile platforms by the Qt5 framework is planned.
Project homepage: http://www.librecad.org
Code repository: https://github.com/LibreCAD/LibreCAD
Online Forum: http://forum.librecad.org
Bug tracker: http://sourceforge.net/p/librecad/bugs