I'm trying to configure Eclipse + CFEclipse for my ColdFusion IDE and hope to add RDS support. Pages like this one on the Adobe site reference a downloadable extension for Eclipse called ColdFusion Extensions for Eclipse
As of 5/20/2014, Adobe's download page supports version 10 and up with no reference to the extensions. I'm sure this download was buried by the push to CF10 and CFBuilder, but is it in the wild somewhere? I'm not having much luck with Google on this.
RDS is Adobe proprietary so you will need to use CFBuilder to get RDS access. I don't believe the extensions have existed since CF Builder was introduced. CFBuilder has a 90 day trial version available and with CF11 you get a free CFBuilder licence with standard edition and 3 free licences with enterprise edition.
Personally I would recommend Sublime Text and the Coldfusion plugin for it.