Sitellite

Sitellite CMS is your basic PHP/MySQL CMS. Seems to make a big deal about multilingual features, so I guess that's its main raison d'être. It's open source, GPL.

From the website:

Cross-platform WYSIWYG editor
Sitellite lowers the learning curve of Content Management with an easy-to-use, standards-compliant in-browser word processor.
"Undo" button!
Never lose a change or delete a page by accident again! Sitellite keeps every change you make in its automatic version control system.
Fine-grained access control
Sitellite has an extremely flexible access control and workflow system that works well for websites with anywhere from just one to hundreds of contributors.
Flexible development model
Sitellite's core is a flexible and modern PHP application framework with tight integration between applications and with the core system, as well as "Web 2.0" features like AJAX support.
100% multi-lingual
Sitellite 5 features a built-in translation interface for all content types, including workflow notices for translators to update changed content. Existing Sitellite sites can be converted to multilingual in just minutes.

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