The DIII-D tokamak evolved from the earlier Doublet IIIdevice in 1986. Since then, the facility has undergone a number ofchanges including the installation of divertor baffles and pumpingchambers in the vacuum vessel, the addition of a radiation shield, thedevelopment of extensive neutral beam and RF heating systems, and theaddition of a comprehensive plasma control system. The facility hasbecome the focus of a broad fusion plasma science researchprogramme. An integrated picture of the facility and its capabilitiesis presented.