LibreCAD

LibreCAD是一个免费的开源CAD应用程序，适用于Windows、苹果和Linux。

Open Source 2D-CAD
LibreCAD is a free Open Source CAD application for Windows, Apple and Linux. Support and documentation are free from our large, dedicated community of users, contributors and developers.

How it started
LibreCAD started as a project to build CAM capabilities into the community version of QCad for use with a Mechmate CNC router.

Since QCad CE was built around the outdated Qt3 library, it had to be ported to Qt4 before additional enhancements. This gave rise to CADuntu.

The project was known as CADuntu only for a couple of months before the community decided that the name was inappropriate. After some discussion within the community and research on existing names, CADuntu was renamed to LibreCAD.

Porting the rendering engine to Qt4 proved to be a large task, so LibreCAD initially still depended on the Qt3 support library. The Qt4 porting was completed eventually during the development of 2.0.0 series, thanks to our master developer Rallaz, and LibreCAD has become Qt3 free except in the 1.0.0 series.

Meanwhile, for LibreCAD 2.2.0 series, Qt5 is mandatory.