Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Adobe Illustrator CC - Adobe Illustrator CC is a commercial vector graphics editor.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Boxy SVG - Boxy SVG is a vector graphic editor built for the modern web.
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project