The WYSIWYG Editor - What you see is what you get - is one of two available editors for creating page content. Jojo uses the Open Source Xinha Editor. The picture below shows the main editor functionalities.
image of wysiwyg editor

The editor use similar icons as word or open office does, so it is intuitive for users. User can either create the content with visual support or see the HTML Source Code. Although a list of available CSS classes is visible in the editor.
Furthermore you can and paste plain text or text of Microsoft Office Documents and clear the MS OFfice Tags with the editor.

For further developer information you can visit the Xinha Editor website.