Willow

Willow has been designed to meet the needs of both front-end and back-end developers by providing a small, yet powerful set of tags and tools to speed up template development and prototype iteration, and is influenced by other template engines, most notably Mustache.

All Willow tags include a matching opening and closing pair, starting and ending with a curly bracket and one other internal character.

Willow was designed to meet several specific front-end and back-end developmental needs. 

Willow uses it's own proprietary file extension - .willow - and provides two filters to register custom and native templates with WordPress for admin selection and frontend rendering.

The location and structure of certain files are very important to how Willow works, so understanding the lookup process is equally important.

Context and task are two key aspects of Willow, they are equivalent to Class and Method in PHP and all Willows retrieve data from a single public php method within a class

Willow has its own dedicated logging system and syntax and can be configured to write to the WordPress debug.log, which is located in the root of the wp-contents directory.

By default, if the data returned to a willow is not in a format that can be rendered, either a string, integer or boolean or an array of strings, integers or booleans and indexed arrays of strings, integers or booleans, the willow is not rendered.