Tagged collections are collections of items tagged with multiple categories. libtagcoll provides general infrastructure to handle tagged collection data, plus various kind of tagged collection manipulation functions:

* apply various kinds of transformations to the collection;
* generate and apply tag patches;
* discover and show implicit hierarchical relationships between
tags;
* organize the collection in an intuitively navigable hierarchy.
* keep an on-disk index of the tag data
warning: the api has not yet been stabilized and is subject to change in future versions. this is why the library is distributed in a -dev package only.