Gwennel is a WYSIWYG and WYSIWYM editor that works with Windows PCs.
Compatible with Open Document Format (ODF), Gwennel primarily uses WYSIWYM, an alternative to the traditional WYSIWYG (which, incidentally, stands for What You See Is What You Get). WYSIWYG editing programs allow you to see what you're doing as you're doing it in the style editor. WYSIWYM, on the other hands, is an acronym for What You See Is What You Mean. It tends to be more structured in terms of how it allows the writer to add content. In WYSIWYM formatting, content is written according to its meaning and its significance in a particular document, as opposed to specifically existing to design the appearance of the content in question.
WYSIWYM's main advantage is the wholly separate presentation and content that derives from it. Users can focus on writing and structuring the document as opposed to concerning themselves with the document's appearance. In this way, a WYSIWYM document can be more easily and widely exported for future use.
Gwennel allows users to enter text and edit it to include pictures, links, and tables. Gwennel's left side panel is where you can see these various elements reflected. There, a tree diagram shows the options to configure each different element you've input into Gwennel.
Unfortunately, some of Gwennel's more advanced options are not very easy to figure out if you're new to this style of editing. Some practice and toying around with different features in Gwennel is definitely required before it all will likely start to make sense to most users.
Gwennel's interface is still very usable, especially if you're looking for an ODF-compatible text editor.