Most digital libraries are about digitalized artifacts. Books, images, music, film. Some are about born digital artifacts. Mailing lists, digital documents, annimations, etc.
Monica McCormick notices that the California Digital Library’s Counting California project goes back to what computers used to do — munch and crunch and rearrange numbers. Counting California gives you access to all kinds of databases and spreadsheets that you can download and work with using a variety of applications.