There are some good frameworks available like this one from my friend Fred Polgrady, http://github.com/sustainablecode/datastore
I will provide an easy way of installing Rhino on a mac. Follow these three steps for an easy installation...
1. Download Rhino
2. Create "Java/Extensions" in home directory "~/Library/Java/Extensions"
3. Copy the js.jar file from the downloaded Rhino zip file to "Extensions" directory.
Thats it!! You are all set to use Rhino.
Rhino 1.7 release 2 2009 03 22