SPIP

SPIP is an open source content management and collaborative editing application.

SPIP is a publishing system for the Internet in which great importance is attached to collaborative working, to multilingual environments, and to simplicity of use for web authors. Originally a Content Management System, it has gradually become a development platform making it possible to create maintainable and extensible interfaces independently of the structure of the managed data.

Features:

Typographical Images: SPIP can automatically convert titles (or other text elements from the database) into images, using the font of your choice.
LaTEX mathematical formulae: SPIP has a powerful functionality that allows complex mathematical formulae to put inserted into text using the syntax defined for TEX/LaTEX.
Content Syndication: Share the attached document urls (podcasting), transfer keywords (tags) from one site to the other as well as the section (or category) of the articles.
Multi-lingual: To give the flexibility for all these different situations, SPIP allows the language to be set for each section, article and news item.