Please refer to the following thread: http://www.aptana.com/forums/viewtopic.php?t=3700 Basically, RadRails should get its list of environments from the database.yml file. Currently, it is possible to type a custom environment into server configuration, but the pre-populated list should come from database.yml. Similarly, it should be possible to select an environment for Rake tasks rather than having to type in RAILS_ENV="environment_name". It would appear than this issue also affects the Data Navigator, and the debugger.