Pingendo, a native application for Windows and Mac, uses Twitter Bootstrap as a base for drag-and-drop HTML editing. I was just wishing this tool existed last week as I tried to beat Axure into working as well as hand-coding my own mockups.

If it's as good as it looks at first glance, this could be a perfect tool for designers in engineering/business-process-heavy enterprise environments.

Free while in beta: http://www.pingendo.com