By default, the latest version of RiskTree loads, stores, and saves RiskTrees in JSON format. RiskTree continues to support the MindMap XML format, which is a standard output from many commercially available mind mapping tools. The data structure is very simple, and based around the <node> tag. The information in the node is held in a TEXT attribute.

Each child node has a <node> tag nested within its parent <node> tag. This nesting continues until an end node is reached; here, a closed <node /> tag is used. To reverse back up the tree, closing </node> tags are used.

Assessment values are placed into the end nodes separated by forward slashes. They need to be separate from the node name by a line feed character, which is encoded in XML as &#10;. These XML tags also need to be closed, which is most easily achieved by including a final forward slash before the closing angle bracket. This is best demonstrated by an example:

The XML for this attack tree looks like this:

				<map version="0.9.0">
					<node text="Steal from museum">
						<node text="Internal">
							<node text="Bribe guard&#10;4/3/4/5/6/1" />
							<node text="Get job in museum&#10;2/4/2/6/6/0" />
						<node text="External">
							<node text="Stay behind after closing&#10;1/2/3/5/5/1" />
							<node text="Break in...">
								<node text="Through window&#10;1/3/5/5/5/1" />
								<node text="Through door&#10;1/2/4/5/5/1" />

The indentation, using tabs, is not required. It is used in this example to make the nesting of the <node> tags easier to see. For example, the three </node> tags at the end of the file close, respectively, the Break in..., External, and Steal from museum nodes.