Wireframe.cc - Sweet and simple online wireframing tool.
SVG Animation Assistant - Quickly and easily animate Inkscape SVGs.
WireframeSketcher - WireframeSketcher is a wireframing tool for creating wireframes, mockups and prototypes for desktop, web and mobile apps. It's a desktop app for Mac, Windows and Linux, and a plug-in for any Eclipse IDE.
Vectr - Free vector graphics editor. A simple yet powerful web and desktop cross-platform tool for everyone.
Saola Animate - Easily create engaging HTML5 animations and interactive web content without coding skills
Hype - Using Hype, you can create beautiful HTML5 web content.