The XML plugin provides a SideKick tree structure browser for editing XML, HTML, CSS, JSON, and JavaScript files, and completion for XML, HTML5 and CSS3.
Matching tag actions, pretty-printing, graphical editing of tag attributes and conversion of special characters to entities and vice versa are supported for both XML and HTML files.
XML files are validated against their DTD, XSD, or RNG. Validation errors are shown in the Error List.