Abstract: A decking system, decking components and an installed deck for use on a support structure. The decking system comprises hollow profile planking units having anchor flanges on opposite edges that cooperate with an anchor structure to form a deck or platform. The flanges and the anchor units are shaped and configured to closely interact and form an installed platform structure. The planks comprise an extruded thermoplastic wood fiber composite having an internal structure sufficient to withstand installation, engineering forces placed on the installed platform, weathering and use. The anchor structures have a shape that conforms to the anchor flanges on the decking profiles to hold the deck in place.