Can I develop Access 2000 an 2003 applications in Access 2007 using the right compatibility mode? I know I could run the aspps in 2007 but can I develope and maintain previous versions in 2007?

You can develop for earlier versions with A2007 but you must be very careful to ensure compatibility by not using functions, methods, and properties that were not available in earlier versions. Make sure you have a test system with A2K installed and A2003 so you can test the app in the native environment.

You can develop for earlier versions with A2007 but you must be very careful to ensure compatibility by not using functions, methods, and properties that were not available in earlier versions. Make sure you have a test system with A2K installed and A2003 so you can test the app in the native environment.
What do you mean by a test system installed? Do you mean have all three versions of Access installed on one machine? I thought this caused problems. :confused:

If your users are going to run the app with A2K, then that's the version you need to use to test the app. You could use virtual PC to run A2K and that way the environment would be isolated from your PC.