It will be common to work on more than one Ruby on Rails application at the same
time.  However, when you switch back and forth between them and use the "Run
Main Project" option, the application visible via WEBrick does *not* change.

Steps to reproduce:
* Create RoR application "example1"
* Add some models, views, controllers, and deploy
* In the browser, see that you can get to these pages
* Create RoR application "example2"
* Add some models, views, controllers with different
  names than those in "example1".
* Deploy with "Run Main Project" and attempt to access
* The controller names from example2 do not resolve,
  but the names from example1 still do.  This implies
  that you're still talking to the WEBrick started for
  example1.