A free, open-source tool for collecting, organizing and citing research sources.
Zotero saves books, articles and web pages to a personal library, keeps their metadata tidy, and inserts formatted citations and bibliographies into your writing. It runs on Windows, macOS and Linux with browser connectors and optional cloud sync.
The desktop app works offline without one; an account is only needed for sync and group libraries.
The software is free; only extra cloud storage beyond the free quota is paid.
Information and links are accurate as of the time of writing and may change. Always verify on the official site. This is an independent guide, not affiliated with the listed services.