JSR 166 Introduction.

See: Description

Packages 
Package Description
java.util  
java.util.concurrent
Utility classes commonly useful in concurrent programming.
java.util.concurrent.atomic
A small toolkit of classes that support lock-free thread-safe programming on single variables.
java.util.concurrent.locks
Interfaces and classes providing a framework for locking and waiting for conditions that is distinct from built-in synchronization and monitors.