This was briefly discussed [previously on this site][1].  You can find discussions of it in:

 1. Chapters 6 and 17 of Frenkel and Ben-Zvi: <i>Vertex algebras and algebraic curves.</i>
 2. Section 2.6.5 of Beilinson and Drinfeld's <i>Quantization of Hitchin's Integrable system</i> (available online)
 3. Section 2.9.9 of Beilinson and Drinfeld's <i>Chiral Algebras</i>.

  [1]: http://mathoverflow.net/questions/518/what-is-the-connection-between-d-modules-and-coordinate-bundles/523