Gecko 1.8 (Firefox 1.5, SeaMonkey 1.0) supports URL values for the CSS cursor property on Windows and Linux. Mac support was added in Gecko 2 (Firefox 4). This allows specifying arbitrary images as mouse cursors — any image format supported by Gecko can be used.
The Node.lastChild read-only property returns the last child of the node. If its parent is an element, then the child is generally an element node, a text node, or a comment node. It returns null if there are no child elements.
A processing instruction provides an opportunity for application-specific instructions to be embedded within XML and which can be ignored by XML processors which do not support processing their instructions (outside of their having a place in the DOM).
getAttributeNS returns the string value of the attribute with the specified namespace and name. If the named attribute does not exist, the value returned will either be null or "" (the empty string); see Notes for details.
Identifies the current target for the event, as the event traverses the DOM. It always refers to the element the event handler has been attached to as opposed to event.target which identifies the element on which the event occurred.
The Node.firstChild read-only property returns the node's first child in the tree, or null if the node is childless. If the node is a Document, it returns the first node in the list of its direct children.