I decided to try social JRebel for an open-source, personal project and I cannot get this working.
I use Eclipse Indigo IDE and I have downloaded JRebel via Eclipse marketplace and activated JRebel with my free license. I have setup the Glassfish application server with enable JRebel and disable auto publish.
Here is my rebel.xml
<?xml version="1.0" encoding="UTF-8"?>
<application xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.zeroturnaround.com" xsi:schemaLocation="http://www.zeroturnaround.com http://www.zeroturnaround.com/alderaan/rebel-2_0.xsd">
<classpath>
<dir name="D:/workspace/jee/catiJava/src/ro/cati/actions"></dir>
</classpath>
<web>
<link target="/">
<dir name="D:/workspace/jee/catiJava/WebContent">
</dir>
</link>
</web>
and my project structure looks like this

The problem is that after I change something in DashboardAction.java which is under the package ro.cati.actions as a source nothing happens. I still have to redeploy in order to see the actual changes.
Instead of the source directory you should have the compile/build directory in <classpath> of your rebel.xml. So for example if the classes in src/ get compiled to bin/ you should have:
JRebel works with the compiled .class files and depends on the IDE to compile them.