The OPML Editor is an outliner, an editor that works with chunks of text that slide around on rails. You can control the level of detail you look at, and reorganize according to structure. It's great for writing blog posts, technical notes, program code, legal briefs, product plans, to-do lists, entire websites, anything where ideas need organization.
Leo is... * A general data management environment. Leo shows user-created relationships among any kind of data: computer programs, web sites, etc. Leo shows multiple views of data within a single outline. * An outlining editor for programmers. Leo supports optional noweb and CWEB markup. * A flexible browser for projects, programs, classes or any other data. * A project manager. * Fully scriptable using Python. * Leo's outline files are XML format.
XOXO (eXtensible Open XHTML Outlines) is an XML microformat for outlines built on top of XHTML. Developed by several authors as an attempt to reuse XHTML building blocks instead of inventing unnecessary new XML elements/attributes, XOXO is based on existing conventions for publishing outlines, lists, and blogrolls on the Web. The XOXO specification defines an outline as a hierarchical, ordered list of arbitrary elements. The specification is fairly open which makes it suitable for many types of list data. E.g. the more semantic version of the S5 presentation file format is based upon XOXO.
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.