Theme_Handlebar is a child theme of Moodle's new core theme Boost.
It is built on Bootstrap4 and Mustache templates.
It adds a set of admin theme settings, such as presets and colours and also several custom block regions, including popup modal regions which do not appear on the main content of a page (and are only available for course pages).
Theme_Waxed is a child theme of Moodle's new core theme Boost.
It is built on Boostrap4 and Mustache templates and adds additional settings to those in Boost to allow a level of customisation with limited knowledge of scss/css.
This is the flexibase theme for Moodle. It is a Bootstrap3 theme, but uses flexbox to create the layouts, rather than the bootstrap grid.
This theme depends upon Bas Brands' bootstrap theme for bootstrap3.
MultiLayout is a theme with minimal styling which enables various 1, 2 or 3 column page layouts to be used from within the single layout file with little recoding (one line to be uncommented). It is intended to be used as a parent theme for further styling (in the same manner as Base/Standard) rather than as a complete site theme on its own.
Alongside the multiple layouts, it also has additional block regions above and below main content to provide maximum flexibility for the layout of any page.
Buckle is a basic theme which uses bootstrapbase as its parent. It is designed to be built onto rather than as a 'finished' production theme in a similar manner to the 'standard' and 'clean' themes in core.
It takes bootstrapbase and adds the responsive version of the 3column HolyGrail layout.