Org Mode

Org Mode is a number of things:

• it's a text format for outlining and lists somewhat similar to markdown
• it's an Emacs mode and suite of functions to manipulate and manage that format

At first blush it may seem that org mode is not software agnostic since it's heavily associated with Emacs, but I think on further reflection it is because it's text based. Emacs is just the most sophiticated software to manage it but it's still easy to read and manupulate without Emacs.

For example, there exists a parser written in Javascript for org mode files, and pandoc can handle it too.