Bookends

Bookends is a macOS‑native reference manager that lets users collect, organize, annotate, and cite scholarly resources. It can import references and PDFs from a range of academic sources such as PubMed, Google Scholar, JSTOR, arXiv, and the Library of Congress, and it supports synchronization with its iOS companion and with external citation tools.

The software structures libraries with unlimited hierarchical folders and smart groups, and it can attach and rename PDFs, images, and other documents in a central location. Its built‑in PDF reader provides markup and annotation features that are linked to the interactive note stream, and annotations can be extracted with deep links for use in other applications.

Bookends integrates with word processors like Microsoft Word, Mellel, and Nisus Writer Pro, and it can exchange references with EndNote, Papers, Sente, Zotero, and Mendeley. AppleScript support and link creation between related items enable custom workflows and easy navigation of citation networks.