UXpin - Design is really about solving problems. UXPin is the UX Design Platform that gets that right.
Inkscape - Inkscape is a free, open source professional vector graphics editor for Windows, Mac OS X and Linux.
Figma - Team-based interface design, Figma lets you collaborate on designs in real time.
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
Moqups - The most stunning HTML5 app for creating resolution-independent SVG mockups, wireframes & interactive prototypes for your next project
Cinema 4D - Cinema 4D is a 3D modeling, animation, motion graphics and rendering application.