We all know how WYSIWYG editor work, in which the users have to lay out the text in such a way that we can see it just as we finally want to have it. With the WYSIWYM (What you see is what you mean) format it will be the system that takes charge of laying out the text following the necessary conventions and standards.
Having these two kinds of writing paradigms, Gwennel is one of the most interesting programs when it comes to writing texts. Specially when dealing with mathematical texts, the writing of which can make them a lot more comprehensible if it is done properly.
To sum up, how the WYSIWYM text processors work is what users should ask for as time goes by, and as times goes by more and more processors are taking this into account. If you want to make the most of that format, Gwennel is one of the best options available.