  A detailed description of the infinite-dimensional Lie algebra of star-gauge
transformations in noncommutative Yang-Mills theory is presented. Various
descriptions of this algebra are given in terms of inner automorphisms of the
underlying deformed algebra of functions on spacetime, of deformed symplectic
diffeomorphisms, of the infinite unitary Lie algebra, and of the algebra of
compact operators on a quantum mechanical Hilbert space. The spacetime and
string interpretations are also elucidated.
