This wiki software is free and open source and comes with WYSIWYG features.
Wikiwig boasts a range of features, including a link editor for external and internal links, image manager for upload, rotation, resize, crop, and visual browsing, complex table editing, html view, html tidy (for copy-paste from MS Word for example), and conflict prevention system (lock) that prevents two authors from editing the same page at the same time.
Moreover, Wikiwig makes page and folder creation and deletion easy, folder moving (pages in the future), multilingual interface (French, English, German, and Simplified Chinese), simple automatic install on most hostings, and versioning (restoration via the web in v5.0).
To run Wikiwig, you need PHP 4.1 or later and MySQL 3.2 or later. If you're tired of learning different syntaxes to edit wikis, Wikiwig might be the perfect software for you.
Version 5.01: N/A