1. A computer-implemented method to access a tree data structure in a computing environment, the method comprising: generating the tree data structure in the computing environment, the tree data structure having: a plurality of nodes, a node in the plurality of nodes embodying a plurality of fields for a plurality of data types, and at least one child link and at least one next link, the at least one child link and the at least one next link being used to link two or more nodes in the plurality of nodes; accessing contents of the tree data structure with a single command in the computing environment, the single command including: a reference to at least one node of the tree data structure, a first user-defined argument representing at least one of: a particular property of the at least one node, or a relation of the at least one node to at least one other node, and a second user-defined argument representing at least one of: a command to access contents of the tree data structure by following one or more child links in the tree data structure and one or more next links in the tree data structure, a command to access contents of the tree data structure by following one or more child links in the tree data structure and not following a next link in the tree data structure while the next link is present, or a command to access contents of the tree data structure by following one or more next links in the tree data structure and not following a child link in the tree data structure, the single command accessing contents of the tree data structure based on the first user-defined argument and the second user-defined argument; and providing in the computing environment the contents of the tree data structure based on the single command.