The UI Framework supports a "development mode" that helps you iterate rapidly on web-layer functionality, by automatically recompiling controllers as you edit them, and automatically reloading views. Note that development mode only automatically recompiles controllers (for pages or fragments), not other classes. But you should be iterating on your module's domain objects and service layer using the unit testing framework anyway. :-)
OpenMRS SDK users
If your development environment is setup using the OpenMRS SDK, then this step is even easier for you. All you need to do to enable UI framework development mode is run
mvn openmrs-sdk:watch -DserverId=myserver
For more information on that see the Watch projects section of the SDK documentation.
Manual configuration(Non SDK users)
If you are not currently using the SDK for development(which we strongly recommend), then follow these instructions instead.
To enable development mode for a particular module, you need to set an argument at runtime before starting up OpenMRS.