CSL 1.0.1 is an (almost completely) backwards compatible release, and CSL 1.0 styles and locale files don’t have to be updated to work with CSL 1.0.1-compatible software. CSL 1.0.1 is a relatively minor update, but adds a variety of new features to CSL, and an extra layer of polish to both the specification and schema. The CSL 1.0.1 specification is accompanied by CSL 1.0.1 release notes, which give a comprehensive overview of the changes in this update.

State of the Union

This is the first update of the CSL schema since the release of CSL 1.0 in 2010. While CSL development has slowed since the flurry of activity leading up to the release of 1.0, we consider the project to be in great shape. CSL 1.0 has proven to be a very popular release, and we now have a well-curated collection of over 2500 CSL 1.0 styles, many of which have been contributed by users. All styles are now available under the permissive Creative Commons Attribution-ShareAlike license. A redesign of the Zotero Style Repository page has made browsing and searching styles easier. CSL 1.0 is now supported by Zotero, Mendeley, Papers, and Qiqqa, and we expect that these programs will support CSL 1.0.1 in the near future.

In addition to Frank Bennett’s citeproc-js, used by Zotero, Mendeley, and Qiqqa, there are several other actively maintained open source CSL processors. The PHP-based citeproc-php by Ron Jerome offers CSL support in Drupal through the Bibliography Module. The Haskell-based citeproc-hs by Andrea Rossato adds CSL support to the versatile Pandoc document converter. Finally, the Ruby-based citeproc-ruby, by Sylvester Keil, can easily be deployed for the web, and has recently been accepted as a 2012 Google Summer of Code project .

A collaboration between Columbia University Libraries and Mendeley is underway to create a more user-friendly CSL editor (although this previously has proven to be quite the challenge). Another exciting development is the work of Frank Bennett on his forks of Zotero and CSL to revolutionize the field of multilingual and legal citation management, the progress of which can be followed on his website citationstylist.org.

With so many parties on board, the main challenge for the next few months will be the creation of a CSL 1.0 style repository, similar to the existing Zotero Style Repository for CSL 0.8.1 styles. Preferably, this repository should use a decentralized version control system like Git to handle the distribution and contribution of CSL styles, and have a front end for users to browse, preview and install styles. Interested parties are strongly invited to participate in the xbiblio mailing list to discuss and help out with these future improvements.

The CSL 1.0 specification update of 2010-05-30 includes the following changes:

• clarified behavior of the line-spacing and entry-spacing attributes [diff]
• clarified behavior of the position condition when used for bibliography formatting [diff]
• clarified behavior of the et-al-subsequent attributes [diff]
• changed the handling of name suffixes (now aligns with Chicago Manual of Style) [diff]
• changed et-al abbreviation to use a context-dependent prefix (aligns with CSL processor in Zotero 2.0) [diff]
• clarified the behavior of the choose element, and mentioned the dual effect of the match attribute on if and else-if elements [diff]
• removed the substitution of empty date variables by the “no date” term [diff]

Discussions on these changes can typically be found at the xbiblio mailing list.

A Note on CSL Versioning

A three-number system (e.g. “1.2.3″) will be used for versioning of the CSL schema and specification. The first and second number are used for respectively major and minor backwards incompatible updates to the CSL schema (these updates will require upgrading of existing CSL styles). The third number is used for small backwards compatible updates. Each update to the CSL schema will be accompanied by an updated CSL specification. In addition, minor date-versioned updates to the CSL specification can be released without accompanying changes to the CSL schema (as is the case for the current specification update).

A New Home

CitationStyles.org is the new home of the CSL project, hosting the schema, documentation, project news, and more. In the near future CitationStyles.org will also host the style repository currently found at www.zotero.org/styles.

By Academics, for Academics

CSL 1.0 has been developed by academics, for academics. The members of the development team hail from diverse fields, covering social science, law, and natural science. We are keenly aware of the diverse and demanding requirements of scholars working in different languages and different fields of research. At the end of an intensive year of development work, we feel confident that CSL 1.0 marks an important step forward in academic productivity.

New features

The top 5 new features that we would like to highlight:

• In-field markup: CSL 1.0 compatible programs now support markup within titles, with support for ^superscript, _subscript, small capitals, italics and boldface.
• Full localization: whereas CSL 0.8 only offered localization of terms, CSL 1.0 offers full style localization, adding support for localized dates and punctuation.
• Names: many new features are related to names. Name disambiguation has been refined, and name particles (“van” in “Ludwig van Beethoven”) can now be sorted and rendered according to conventions that reflect the culture and personal preferences of each author.
• Documentation: the schema for the 1.0 release is accompanied by a full set of documentation. A specification gives all the details on CSL 1.0, and upgrade notes discuss the changes made between CSL 0.8 and 1.0. A primer offers a concise tutorial on editing CSL 1.0 styles.
• CSL processors: CSL 1.0 is released alongside citeproc-js, the first CSL 1.0 compatible CSL processor, as well as a CSL 1.0 test suite. Various features of CSL 1.0 and citeproc-js can be seen in action in the online demo. Adding support for CSL was never easier.

CSL 1.0 includes many more improvements. For a full overview, see the upgrade-notes.

Using Existing Styles

Zotero support for CSL 1.0 is scheduled for Zotero 2.1. When released, the Zotero team will upgrade the more than thousand CSL 0.8 styles hosted in the Zotero Style Repository. To upgrade a CSL 0.8 style yourself, follow the upgrade procedure.