Chromeless - Build Your Own Browser UI Using HTML, CSS and JS
Chromeless is experimental toolkit which will allow developers to build their own Web browser using standard Web technologies: HTML, CSS, and JavaScript. The current implementation is a remix of Atul Varma’s Cuddlefish Lab and the Jetpack SDK, combined with XULRunner. Leveraging these existing Mozilla technologies made it possible for us to quickly get to a point where we could launch a XULRunner based application that is a blank canvas — chromeless.
Currently they have a functional pre-alpha prototype that is capable of loading an HTML page and rendering browser UI. In the coming months they will add specific APIs to allow for more meaningful browser construction.They will investigate how they can integrate security features to keep Web content in a minimally privileged sandbox.
Source: http://mozillalabs.com/chromeless/2010/10/21/chromeless-build-your-own-browser-ui-using-html-css-js