Seeing through XHTML
Xylescope turns rummaging through the technical definition of XHTML into child's play

The W3C specifies the syntactical structure of XHTML in so-called Document Type Definitions (or DTDs for short). Because their structure is very involved, DTDs are difficult to read.
This is where Xylescope with its DTD Viewer comes in. If the technical definitions provided by W3C have always been a closed book, now you can look forward to studying with ease the element and attribute structures of all three "flavors" of XHTML 1.0 and comparing them with each other.
The DTD Viewer helps find which elements are valid as children of a given element, which attributes belong to which element and how the entirety of HTML elements has been categorized by the authors of the XHTML standard.
The DTD Viewer is opened by selecting the desired "flavor" from the
menu. Several DTDs can be opened simultaneously.