Expert-level MODX Revolution CMS development, templating, and content management. Use this skill when building MODX websites, creating templates/chunks/snippets, configuring extras (pdoTools, MIGX, ClientConfig, SEO Suite, Image+, FormIt), writing MODX tag syntax, implementing schema markup, or troubleshooting MODX issues. Triggers include "MODX", "pdoResources", "pdoMenu", "MIGX", "ClientConfig", "FormIt", "Image+", "ImagePlus", "chunks", "snippets", "TVs", "template variables", or any MODX CMS development task.