downplay-mode

Downplay mode is a minor mode for Emacs. It allows you to apply a face to an entire buffer, excluding the region or the current line. I generally use it to focus attention on sections of a buffer during a demo or presentation.

See it in action

Learn more

By reading the docs for the mode directly.

Install

The latest version is 0.1, and is available via Marmalade, MELPA, and MELPA Stable:

M-x package-install RET downplay-mode RET

License

See here.