Authors:
Configurable MODX plugin that cleans up (X)HTML source code output.
Utilises hmtLawed by Santosh Patnaik. Originally based on the WP Beautifier plugin for Wordpress by Till Krüss.
Install via MODX package manager and change settings via Settings > System Settings.
Full detailed documentation available at: http://www.goldcoastmedia.co.uk/tools/modx/xhtml-beautify/