13 Zotero
Zotero is a free, open-source reference management tool designed to help researchers collect, organize, annotate, cite, and share their work. * Zotero is available as a standalone desktop application for Windows, macOS, and Linux, with official mobile apps for iOS and Android. * Your library can be synchronized across devices (desktop, web, and mobile). * A free-tier Zotero account provides full access to all software features, with the only primary limitation being cloud storage for file attachments. * You can create Zotero Groups to collaborate on shared bibliographies with colleagues using the Web Library.