What is Chapter 9 Bankruptcy?

According to Bankruptcy Basics published by the United States Bankruptcy Court:
“Chapter 9, entitled Adjustment of Debts of a Municipality, provides essentially for reorganization, much like a reorganization under chapter 11. Only a "municipality" may file under chapter 9, which includes cities and towns, as well as villages, counties, taxing districts, municipal utilities, and school districts.”
(http://www.uscourts.gov/bankruptcycourts/bankruptcybasics/process.html)