Org is a mode for keeping notes, maintaining TODO lists, and project planning with a fast and effective plain-text system. It also is an authoring system with unique support for literate programming and reproducible research.
Org is implemented on top of Outline mode, which makes it possible to keep the content of large files well structured. Visibility cycling and structure editing help to work with the tree. Tables are easily created with a built-in table editor. Plain text URL-like links connect to websites, emails, Usenet messages, BBDB entries, and any files related to the projects.
Org develops organizational tasks around notes files that contain lists or information about projects as plain text. Project planning and task management makes use of metadata which is part of an outline node. Based on this data, specific entries can be extracted in queries and create dynamic agenda views that also integrate the Emacs calendar and diary. Org can be used to implement many different project planning schemes, such as David Allen's GTD system.
Org files can serve as a single source authoring system with export to many different formats such as HTML, LaTeX, Open Document, and Markdown. New export backends can be derived from existing ones, or defined from scratch.
Org files can include source code blocks, which makes Org uniquely suited for authoring technical documents with code examples. Org source code blocks are fully functional; they can be evaluated in place and their results can be captured in the file. This makes it possible to create a single file reproducible research compendium.
Org keeps simple things simple. When first fired up, it should feel like a straightforward, easy to use outliner. Complexity is not imposed, but a large amount of functionality is available when needed. Org is a toolbox. Many users actually run only a (very personal) fraction of Org's capabilities, and know that there is more whenever they need it.
All of this is achieved with strictly plain text files, the most portable and future-proof file format. Org runs in Emacs. Emacs is one of the most widely ported programs, so that Org mode is available on every major platform.
There is a website for Org which provides links to the newest version of Org, as well as additional information, frequently asked questions (FAQ), links to tutorials, etc. This page is located at https://orgmode.org. An earlier version (7.3) of this manual is available as a paperback book from Network Theory Ltd.