Zotero (pronounced zoh-TAIR-oh) is a free, open source citation manager that helps you organize your research and citations across multiple platforms, formats, and projects. It looks for and gathers citation information for any webpage you are viewing, including: books, articles, videos, audio clips, sources from databases, OneSearch, websites (like Amazon), and more. Zotero lives in your web browser and on your computer and lets you quickly and easily save sources with one click. It can even be added as an extension to your Microsoft Word and Google documents.
Unlike other citation managers, Zotero is open source and owned by an independent non-profit organization, not a corporation. This means it takes a more democratic approach to organizing and sharing information and will not prioritize one format or publishing company over others. It also does not sell your data. It truly is an open source resource.
Zotero works great for keeping track of sources across many projects and classes. It also works for single, stand-alone projects, like research papers; however, if you need a single bibliography and are in a hurry, you may want to check out Zotero's ZoteroBib first at zbib.org.