Why would I want to enable remote debugging of my program with the -Xdebug command line option?

So that the debugger can attach to your java process and debug it remotely. There have been two flavors of Java debuggers:

• Old style e.g. jdb. before JDK1.2.
• New style (became available starting JDK1.2, part of JDK1.3) based on JPDA (read all about it here).

Both have supported remote debugging.

For details of -Xdebug see -

http://java.sun.com/j2se/1.3/docs/tooldocs/win32/jdb.html#description.