Use BibDesk to edit and manage your bibliography. It will keep track of both the bibliographic information and the associated files or web links for you. BibDesk’s services will simplify using your bibliography in other applications and are particularly well suited for LATEX users.
Apple's Keynote presentation software makes it easy to create great looking presentations with professional themes, transitions, and charts and tables. If you need mathematics, though, you're out of luck. For some reason, Apple's designers failed to inclu