Zotero is a Firefox add-on that lets its user discover, store, and maintain bibliographic information. It is capable of recognizing certain metadata on a number of sites using supported protocols. These protocols include embedded RDF and COinS. So whenever you visit a site with Zotero installed, metadate for publications can be stored in your personal collection. If you visit an unsupported site, you can still manually add the relevant information into Zotero. Stored bibliographical records can be exported in a number of formats, and Zotero is also capable of creating a bibliography from your records, in RTF, which can be used by Word and other word processors.
Zotero is pretty new, but going by the buzz in the blogosphere, it is extremely promising. No doubt there are numerous details that require attention and fixing. Just visit the boards on the site or read some of the recent blog items mentioning Zotero, to get an impression of what could be done to improve it. However, this is a very new extension, excuse me, add on, and it should be given a chance to get even better than it already is. Compared to EndNote, its ease of use certainly stands out. Going by comments I get during the EndNote courses, ease of use is definitely something EndNote is lacking. Still, right now Zotero is not something I can recommend to people who use EndNote. There are several barriers, all of which are currently known to the Zotero developers, who will no doubt fix these as soon as possible.
First of all, Zotero only works with Firefox 2. Yes, not even with regular Firefox as most people use it right now, but only version 2. At the moment, only a release candidate is out, no official version 2 yet. Tilburg University (my employer) has a policy to only support MS programs, so only Internet Explorer is supported. Which means I cannot recommend Firefox to people with only limited computer expertise.
The second aspect of Zotero that needs work, is its integration with Word. The one reason people keep using EndNote, even though they don't like it that much, is because it is easy to create citations and bibliographies in a text. The integration with Word (again, a Microsoft product which is supported on campus) makes it easy to write an article, insert citations in the proper places, and have EndNote create a good bibliography, using the correct style for a certain publication. Want to submit the article to a different journal? EndNote will change the style of the bibliography for you, in a few seconds.
I think Zotero has a lot of potential though, and could very well become a major competitor for EndNote in the market of bibliographic tools. Most important right now, is Zotero's ability to discover metadata on sites. As soon as metadata is discovered, the user only has to click a button and the information is stored in the Zotero database. Compare this to EndNote, where the user has to enter information manually, if the site does not support EndNote. It is not a matter of EndNote supporting sites, but sites supporting EndNote. In other words, a site has to be willing to provide support, a different approach. Even if the site does support citation export to EndNote, quite often the user has to export the info to a file, then import the file into EndNote. The number of sites that automatically exports data straight into EndNote is still fairly limited.
If you happen to work (study) at Tilburg University and you want to give Zotero a try, you may find it helpful to know which databases/providers Zotero works with. You can extract metadate from the following sites, using Zotero:
ABI
Annual reviews
Blackwell Synergy
IngentaConnect
JSTOR
Oxford Journals
PubMed
Sage Journals
SURFnet Videotheek
A couple of important databases will not yet work with Zotero:
Wiley Interscience
Web of Knowledge
ScienceDirect
Whenever my provider let me post anything, I do an update of my blogpost on Zotero.