SPIP (Système de Publication pour l'Internet) is an open-source content management system for publishing websites. It emphasises collective working, multilingual sites and ease of use for web authors, and is used for institutional, association, personal and commercial sites. SPIP is written in PHP and works with MySQL, SQLite or PostgreSQL. You install it yourself on your own web server; the project site describes a manual installation and an automatic installer file. The maintainers publish new versions regularly.
SPIP began in 2001 at the initiative of minirézo, a French collective defending freedom of expression on the internet. It is developed, translated and documented by a community of contributors; no separate legal entity is named on the pages consulted. The software is free and released under the GNU GPL. Because you run SPIP on your own infrastructure, the site and its data remain under your control.