RefWorks is a web-based bibliography and database manager that allows you to create your own personal database by importing references from text files or online databases and other various sources. You can use these references in writing papers and automatically format the paper and the bibliography in seconds.
Zotero is the only research tool that automatically senses content in your web browser, allowing you to add it to your personal library with a single click. Zotero collects all your research in a single, searchable interface. You can add PDFs, images, audio and video files, snapshots of web pages, and really anything else. Zotero automatically indexes the full-text content of your library, enabling you to find exactly what you're looking for with just a few keystrokes.