Inkscape
Create and edit your own vector graphics. FREE | INKSCAPE.ORG/EN/
Inkscape is a great free program for creating vectors (scalable graphics that won’t blur when you resize them). It’s so good, in fact, that it’s a serious alternative to premium tools like Adobe Illustrator. Simply put, if you can do it in Illustrator, chances are you can do it in Inkscape, and that’s pretty incredible for a piece of free software. If nothing else, give it a try to see how you find it; if it’s not for you, you haven’t lost a thing.
But don’t think it’s a pared-back, limited offering. Inkscape comes with all sorts of tools for manipulating and creating vector graphics including a large range of filters, layering tools, shapes texts and fills.
You can also manipulate image shapes, fill them with gradients, apply filters, group them with other layers, convert them to paths, distort them and so much more. There’s not enough space here to list everything that Inkscape can do, which just attests to how powerful it is. Since Inkscape is an X11 app, it runs a little slow and doesn’t have the intuitive control scheme you might find from some of its commercial equivalents, but once you get the hang of it, the features and (no) cost outweigh the limitations of the interface.