This is NOT a complete theme - it is an area where I am experimenting with the flexbox layout for Moodle. Please note browser support for flexbox is limited. Please ensure you have the latest version of your browser and check http://caniuse.com/flexbox for compatability.
experimental currently links to base as parent for basic css styling, but applies its own page layout through the flexbox model.
The flexbox model itself, and the responsive menu, work equally well if bootstrapbase is used as a parent - although more work would need to be done in overriding bootstrap styles and docking currently (27/7/13) does not work in bootstrapbase themes.