Zotero

Zotero is a free, open source reference manager run by a nonprofit. A browser connector saves the article, book or web page you are viewing along with its metadata and PDF. In the desktop app you organize items into collections, tag them, read and annotate PDFs, and search the full text of your library.

Its word processor plugins insert citations and bibliographies in Word, LibreOffice and Google Docs in thousands of citation styles, which makes it a common choice for theses. Group libraries let a lab or a co-author team share references, and the data can be exported for LaTeX and other tools.

Free cloud storage for attached files is limited, with paid storage or your own WebDAV server for larger libraries. Some imported metadata is wrong or incomplete, so check author names, years and journal titles before submission, especially for items saved from web pages rather than publisher sites.