This tag library includes useful iteration tags that complement the set
of standard iterator tags of the JSP Standard Tag Library (JSTL).
<forCategories> supports the concept of categories, so that
headers and footers can be provided for items that belong to a same category
in the collection.
allows the handling of the items of a collection
in a columnwise fashion. Each iteration makes available as many items
as there are columns, and they are provided such that the ordering
sequence is column-wise.