Literature:

• Beilinson, A., Ginzburg, V., Soergel, W., Koszul Duality Patterns in Representation Theory (compressed dvi file)
• Milicic, D., Lectures on Algebraic Theory of D-modules (dvi file)
• Milicic, D., Localization and Representation Theory of Reductive Lie Groups (dvi file)
• Milicic, D., Algebraic D-modules and representation theory of semisimple Lie groups (ps file) from Analytic Cohomology and Penrose Transform, M. Eastwood, J.A. Wolf, R. Zierau, editors, Contemporary Mathematics, Vol. 154 (1993), 133-168.
• Milicic, D., Classification of irreducible Harish-Chandra modules for SL(2,C) (compressed postscript file) another elementary example
• Soergel, W., Gradings on Representation Categories (compressed dvi file), to appear in the proceedings of the ICM, Zürich, 1994.