The XTC algorithm is a simple and scalable topology control algorithm for wireless ad-hoc networks that does not require knowledge of node positions or a unit disk graph. It operates in three steps: (1) each node orders its neighbors by link quality, (2) nodes exchange these rankings, and (3) each node independently selects its neighbors in the topology based on the exchanged rankings. The resulting topology is proven to be symmetric, connected, and low degree while remaining energy-efficient for communication. The algorithm is implemented and simulated in a scalable wireless network simulation using the XTC topology control method.