Browse the library.
Directories are what a thing is (a podcast, a book, an event). Collections are what it's about (support, experience, leadership). Every resource belongs to a single directory but can belong to multiple collections, so you have plenty of options for browsing.
Directories
/directoryWhat kind of thing it is. Every resource sits in exactly one directory, and each directory has its own page.
Collections
/collectionWhat it's about. Cross-cutting, so a resource can
carry several — and the three groups below are the ones the old
/all-collections/ page used.
Publisher
/publisherThe one disclosure axis. It says who published a resource, not what it's worth — that call is yours.