The list plugin is the lower level plugin that knows how to build lists from the website pages.
The plugin makes use of expression to check whether a page is a candidate for being part of that list. For example, a list made of the children pages of a certain page will use a simple expression such as:
parent(page_path) == "<this page path>"
When the expression is true, the page is added to the list.
The pages can then be sorted using a simple sort mechanism (at this time, it does not work with international languages because that will require a different database context for each language supported!) This works for sorting by date, by title, by author, etc.