Traditionally speaking, Nexus is very much like a wiki system but hides the ugly details from the user. It uses a very clean WYSIWYG editor and/or a markdown editor. The pages are then stored in a Git repository backed database, so you'll have every version of the page and is a snap to backup.
A community-driven framework for managing your zsh configuration. Includes 40+ optional plugins (rails, git, OSX, hub, capistrano, brew, ant, macports, etc), over 80 terminal themes to spice up your morning, and an auto-update tool so that makes it easy to keep up with the latest updates from the community.