An outline view hides parts of a buffer to better display the underlying structure.

Related: CategoryHideStuff

Emacs provides several outline features, some come bundled,
some must be downloaded.

* Hyperbole: a package in GNU ELPA; includes the Koutliner, the most advanced yet simple outliner for Emacs
* OutlineMode: hides blocks of text in a hierarchy
* OutlineMinorMode: hides block definitions in languages such as C/C++
* HideShow: hides block definitions in languages such as C/C++
* OrgMode: the outliner that does everything (PIM, task management, publishing, and more)
* AllOut: extensive outline formatting and manipulation
* FoldingMode: hides blocks marked with <code>{{{</code> and <code>}}}</code>
* KoutlineMode: part of GNU Hyperbole, multi-level, autonumbered, hypertextual outliner
* FoldIngo: a minor folding mode with mouse/menu/face support.
* CategorizingInformationManager: provides ee-outline to operate on outlines
* FoldDwim: a unified user interface for the folding methods of OutlineMode, HideShow, FoldingMode, AUCTeX folding, and NxmlMode.
* TaggingMode: add tags to your file, then filter the blocks shown using tags
* HtmlOutline: shows how to use NxmlMode to fold <ol> based outlines in html.

== Emacs Packages ==
* [https://github.com/jamescherti/outline-indent.el outline-indent.el]: The ##outline-indent## package offers a minor mode for code folding based on indentation levels, providing a fast and reliable alternative to origami.el and yafolding.el.
* [https://github.com/gregsexton/origami.el|origami.el] (not maintained): another text folding mode for Emacs.
* [https://github.com/zenozeng/yafolding.el|Yafolding.el] (not maintained): simple script folding code blocks based on indentation, so, no special strings are needed.
* Enable outline-minor-mode (bundled with GNU Emacs, and with better language support from most major modes than hide-show minor mode): <code>(add-hook 'prog-mode-hook 'outline-minor-mode)</code>
* Install OutlineMagic for sane outline keybindings.