Out today. Completely rewritten from the ground up, with lots of much needed and welcome improvements. Check out the website for the complete list of new features and improvements. Worth mentioning: Papers is becoming more and more a document manager, in addition to a reference manager, you can now store many different file formats. Papers is  taking advantage of all the underlying technology of Mac OSX, the user interface is a delight to use (the opposite of Endnote, if you ask me). The integrated search tools (up to 25 search engines combined) are certainly a great time saver. The deal-breaker will be the integration with word processing document, which is where I find Endnote still superior, so far. We’ll see how it goes. I also hope they finally improved the metadata extraction (that’s what they claim), which is where Mendeley really shines.

Alas, as I am bound to a PC in the lab, I am turning to Mendeley as my sole reference manager software. It syncs seamlessly between computers at home and in the lab. I only using Papers on the iPad to carry my papers with me, but keeping two libraries up to date is a pain. The annotation tools are keeping me with Papers so far. I’ll switch to Mendeley for iPad when:

• I can sync all my library without paying additional fees (my library is larger than the 500Mb free limit, with around 800 papers), and access it without a network.
• Annotation tools are added on the iPad version, and sync with the desktop version.

Competition is welcome in this domain anyway. If I was the Endnote developers, I’d be really worried.