There is a great deal of freely-available data which may be useful to add to your local VuFind® instance. Authority records from large organizations and standards bodies can help augment your index with cross-references, and Open Access publications can expand the collection that you present to your users.
This page links to a variety of open resources that you might find useful, most of which can be harvested and ingested using standard VuFind® tools. Feel free to add new sources as you find them.