Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of LibreCAD, please access the librecad tag and open the latest article (the one on top).
LibreCAD is an open-source, multi-platform, free 2D CAD software available for the most popular desktop platforms: Linux, Windows and Mac OS X. It is available in over 20 languages, has support for DWG files, it is capable of writing DXF files and has support for exporting SVG, JPG, PNG, PDF files, among others.
Also, it has layers, blocks, splines, polylines, ellipse tools, advanced tangent line & circle tools, transformation tools, an advanced snapping system and more. Because LibreCAD focuses on 2D geometry it is fast and lightweight, with an installer of less than 30mb.
The latest version available is LibreCAD 2.1.0, which has recently received support for Ubuntu 15.04 Vivid Vervet.
The LibreCAD maintainer has created PPA which provides the latest LibreCAD packages for Ubuntu and derivative systems, to help the users install librecad and keep it up to date.
The below instructions should work on Ubuntu 15.04 Vivid Vervet, Ubuntu 14.10 Utopic Unicorn, Ubuntu 14.04 Trusty Tahr, Linux Mint 17.1 Rebecca, Linux Mint 17 Qiana, Pinguy OS 14.04, Elementary OS 0.3 Freya, Deepin 2014, Peppermint Five, LXLE 14.04, Linux Lite 2 and other Ubuntu derivative systems.
$ sudo add-apt-repository ppa:librecad-dev/librecad-daily
$ sudo apt-get update
$ sudo apt-get install librecad
Optional, to remove librecad, do:
$ sudo apt-get remove librecad