Classification of Quasifinite Modules over Lie Algebras of Matrix   Differential Operators on the Circle
  We prove that an irreducible quasifinite module over the central extension of the Lie algebra of $N\times N$-matrix differential operators on the circle is either a highest or lowest weight module or else a module of the intermediate series. Furthermore, we give a complete classification of indecomposable uniformly bounded modules. 
Yucai Su