From DT Online
Inkscape is professional quality vector graphics software which runs on Windows, Mac OS X and GNU/Linux. It is used by design professionals and hobbyists worldwide, for creating a wide variety of graphics such as illustrations, icons, logos, diagrams, maps and web graphics. Inkscape uses the W3C open standard SVG (Scalable Vector Graphics) as its native format, and is free and open-source software - why pay more!
Inkscape can be downloaded from www.inkscape.org. The file format that Inkscape uses is compact and quickly transmittable over the Internet. Yet it is powerful and can describe complex drawings that are scalable to any size. Support for the format has been added to web browsers and is already included in many mobile phones.
Most fully functioning design software takes a little bit of getting into but Inkscape is well supported with Tutorials, and social media user groups such as the Community . There are also many 3rd party Video Tutorials on YouTube.