Skim

Skim is a macOS PDF reader tailored for scientific papers but usable with any PDF document. It provides standard viewing capabilities alongside annotation tools such as note creation, text highlighting, and “snapshots” that capture sections for quick reference. Navigation is supported through a table of contents, thumbnail previews, and a visual history, while a reading bar and magnification aid focused reading.

The application includes features for presentation mode with built‑in transitions, preview of internal links, and AppleScript automation. It integrates with LaTeX workflows via SyncTeX and PDFSync, works with BibDesk and other external tools, and stores passwords securely in the macOS Keychain. Notes can be exported as plain text, and remote PDFs are downloaded automatically.

Skim runs on macOS 10.13 or later, offers extensive customization, and supports Apple Remote Control, Spotlight indexing, and smart cropping. Its stable release is intended for users who need a lightweight, annotation‑rich PDF viewer on macOS.