Citation Style Language

Citation Style Language (CSL) is a metaformat for defining formats for bibliographic citations, based on XML. It is used by many programs and utilities that deal with references, including Zotero. Version 1.0.1 is current as of this writing, released 2012-09-03.

Specifications

 * Official spec (this link always goes to latest version)
 * Version 1.0 (2010-03-21)
 * Version 1.0 (2010-05-30) (there were apparently two different 1.0 versions)
 * Version 1.0.1 (2012-09-03)

Other links

 * Official site
 * Wikipedia article