TheGuide

A Minecraft mod which provides a simple ingame documentation API for mod developers to use. Documentation is loaded from markdown files which are treated like any other resource used by Minecraft, which allows them to be altered or expanded by resource packs.

Currently only a very small subset of markdown is supported - links, headers, and plain text. The link syntax has been changed from normal markdown - instead of providing a URL, links contain a standard Minecraft resource path of the form "modname:path/to/markdown/file". A larger subset of markdown syntax will be supported in future versions.

All credit to asie for the idea behind this mod. See http://mc.shinonome.ch/doku.php?id=wiki:blog:state_of_the_pack