Most browsers will show a raw XML file as an element tree, allowing you to open and close branches/elements by clicking on a "+" or "-" symbol to the left of each element.
That requires either building a memory intensive tree model of the XML (DOM), or, repeatedly reparsing the XML every time the user wants to open/close part of the view.
The standard "DOM" methodology requires building a tree node for every element and text chunk between the elements, and maybe for the attributes on the elements (or at least attaching an associative array to each element for its attributes). All of these little pieces fragment memory, unless a very clever compaction and/or string interning setup is used.
That requires either building a memory intensive tree model of the XML (DOM), or, repeatedly reparsing the XML every time the user wants to open/close part of the view.
The standard "DOM" methodology requires building a tree node for every element and text chunk between the elements, and maybe for the attributes on the elements (or at least attaching an associative array to each element for its attributes). All of these little pieces fragment memory, unless a very clever compaction and/or string interning setup is used.