Mozilla's browser building blocks
With Chromeless, the Mozilla developers have presented an in-house technology that can be used to build custom web browsers. The software uses the Jetpack framework, the future standard for Firefox extensions. At present, the complete Firefox browser or the XULRunner is required as a runtime environment, although no user interface is provided for the browser.
Up to now, such customisation has only been possible on Firefox's basic structure via XUL (XML User Interface Language) and XPCOM. The Chromeless code, which the developers call "pre-alpha", is available from a Git repository.
Once installed, examples of home made browsers can be found in the
ui directory. One of them has icons for individual web sites instead of a tab bar (see image), while another illustrates the use of Jetpack's Notify API.