Liquid is a templating system for Rails; one of it’s primary attractions is that, unlike ERb, it’s safe to let your users enter Liquid code. (ERb directly evaluates Ruby code from the markup – that means that your end users could delete files, add and delete records in your database, and worse.)
For more information and usage examples, see chapter 22 of Practical Rails Plugins, or the official Liquid homepage.
Author: jadedPixel technologies inc.
Installation:
ruby script/plugin install http://liquid-markup.googlecode.com/svn/trunk