Thompson Scientific today announced the release of Endnote X1 for Macintosh. New features include Applescript support, group references and better support for Endnote Web. Endnote X1 for Windows was released in June. In addition to the features above, it supports Microsoft Word 2007 and Vista.
Endnote is an essential bibliographic tool for scientific publishing. New versions are released almost every year (for an overview of the different versions read here), and Endnote is expensive (list price $299), even with educational discounts. Are there alternatives for Macintosh users?
Papers searches Pubmed and retrieves and stores PDF files. I'm a happy user and have reviewed it elsewhere. Papers can't help with formatting your bibligraphy, but you can export your bibliography (e.g. to Endnote).
Sente is a great reference manager that integrates with Microsoft Word and Mellel. Many nice touches.
Bookends is the third reference manager for the Macintosh. I have no real personal experience with Bookends, but it also works with Microsoft Word and Mellel.
Most Macintosh users will use Endnote because it is the most mature program, and because their collaborators most like also use Endnote. But because of the high price tag and the sometimes unelegant interface, there might be a market for one of the contenders mentioned above. My personal favorite is Papers, so I hope for citation support in Papers 2.0.