I reasearch modern Ajax Grids capable of grouping rows by fields (into collapsible sections), in a manner similar to ExtJs Grid grouping. Important requirements to such a grid is not only grouping, but grouping (sorting) by multiple fields, e.g. by country and gender. Ideally user needs to be able to select fields to group by (sort by) dinamically. I don't expect grids to do it, but knowing that given Ajax grid at least allows to build such a feature would be good.
Such a grid exists in ASP.Net world - http://demos.devexpress.com/ASPxGridViewDemos/GroupingSorting/Grouping.aspx - see it allows dynamic grouping by dragging required columns to upper bar. But as PHP developer I am not sure such thing exists as pure js-lib or as some PHP library.
What are other grids, except ExtJs grid, that support flexible/nested/dynamic field grouping, for using it in PHP?