When running Coldfusion on OSX with RDS enabled you may receive a 404 error when trying to connect your IDE (CF Builder, Homesite, etc.)
After reviewing permissions and configuration I found that the issue was Apache checking for the existence of the page prior to attempting to run it. The RDS IDE functions/page does not exist because it simply a URL pattern defined in the web.xml file.
An easy fix was to setup a dummy folder/file:
The IDE.CFM page can be blank, Apache just needs to verify the file exists prior to handing it to the Java server for processing.