Full text of the Libby indictment. What is Fitzgerald trying to prove?

When Fitzgerald indicted "Scooter" Libby, he alleged that Libby had committed five crimes. Those crimes were:

• One Count of Obstruction of Justice (18 U.S.C. 1503)
• Two Counts of False Statements (18 U.S.C. 1001(a)(2))
• Two Counts of Perjury (18 U.S.C. 1623)

The indictment itself is shown at Washington Post.

Fitzgerald made a lengthy statement to the Press, the transcript of which was published here.