Java Memory profiling tools

Some useful tools for memory profiling:

Free/Open-source Tools: (In order of preference)

-       MAT (Memory Analyzer Tool): http://www.eclipse.org/mat/ (eclipse update site - http://download.eclipse.org/mat/1.0/update-site/)

-       VisualVM: https://visualvm.dev.java.net/ (Comes as part of later versions of JDK1.6)
-       JMAP: https://olex.openlogic.com/packages/jmap

Commercial Tools: (In order of preference) [Free tools should be good enough to find out major memory leaks]

-       JProbe
-       JProfiler
-       YourKit

Excellent article on memory profiling:
http://olex.openlogic.com/wazi/2009/how-to-fix-memory-leaks-in-java/