Zotero is a bibliographic and research management addin for the Firefox web browser. The latest test release, 2.0b3, succeeds Zotero 1.5b2.1 with some substantial improvements, particularly by increasing Zotero's flexibility and usefulness for research collaboration among several, different Zotero users. In addition to the resources on Zotero's website, Tommy Keene has a good quickstart guide