To compile, first set an environment variable IDEA_HOME pointing to
the top level of your IDEA tree.

e.g.
  declare -x IDEA=/opt/local/idea10
  ant

While in the editor, you call it up with Option-Shift-` (backtick) on the Mac,
or Alt-Shift-` (backtick) on Linux. (Think of it like embedding the output of
a shell command using backticks in the shell.)  It is also available from the
Edit menu, as 'Run Shell Command on Lines', and that should also show what
binding has been applied to it.

If you have text selected it'll pass it to the shell command and replace your
selection with the output. If you don't have text selected it'll insert the
output of the shell command.

If you do silly things, you'll get silly results... e.g. 'sleep 10' will freeze
IJ for 10 seconds! If you do something that freezes for too long, you can kill
that process, and IJ will come back.

As far as I know, it does not work on Windows yet.