Ask HN - open source website builder created in javascript?

Is there a simple open source javascript website builder that I can use in other projects? jQuery UI is a really good starting point, but I wonder if there's anything that took it further. I'm looking for: - simple building blocks (text, headings, bold, italic and images) - grid based drag & drop - nice UI or themable - can read initial positions from a configuration file (so I don't have to generate javascript code from php) - use same code to display the page on the front-end?