Balsamiq Mockups is a small software tool to sketch out user interfaces, for websites and web / desktop / mobile applications. We focus on the ideation phase, making a clean tool that lets you get in the flow and stay focussed on structure rather than colors and icons. Mockups provides enough interactivity to replace prototypes most of the time, and makes it easy to collaborate and get feedback on your wireframes.
Balsamiq aims to be a company that’s human, respectful, transparent, inclusive, socially and environmentally conscious, and a good citizen of the world and the Web. They started in 2008 as a one-man-shop, and have been growing organically ever since.