Gwennel is a free WYSIWYG and WYSIWYM editor for Windows supporting natively the Open Document Format.
Gwennel is not a word processor, its goal is not to produce printed documents. It is more a note taking software to edit electronic documents.
The Guide evolved from the need to have an application that could organize information and ideas in a hierarchical, tree-like structure. Tree-based structures are frequently employed to manage information through a "divide-and-conquer" approach, wherein each level of the tree represents a further level of specialization of the parent-level topic — the best example of this being a book.