LibreCAD is a fully comprehensive 2D CAD drawing tool based on the community edition of QCAD. LibreCAD has been re-structured and ported to Qt version 4 and works cross platform, including Microsoft Windows, Mac OS X and Linux (Debian, Ubuntu, Fedora, Mandriva, Suse).
This is the first, major fixes for the year 2015: a serious command line regression since 2.0.6: keyboard Enter/Esc support, command line widget in a second screen, etc. Also fixed are some crashes for tangential circle drawing and polyline addition. As a new command line feature introduced in 2.0.7, the command line can be used as a calculator by typing math expression after command “cal”. For example command “cal 1+1″ to get output “2″. There are many fixes and enhancement – See release note
Install LibreCAD 2.0.7 on Ubuntu OS
sudo add-apt-repository ppa:librecad-dev/librecad-daily sudo apt-get update sudo apt-get install librecad