EASE - Contributing
To build EASE in Eclipse you should start with 'Eclipse for RCP and RAP Developers'. After startup go to Preferences/Maven/Discovery and click Open Catalog. Afterwards install the Tycho Configurator. If you want to work on the EMF models you might want to additionally install 'EMF Eclipse Modeling Framework SDK' and 'Diagram Editor for Ecore (SDK)'.
After importing you should set your target platform. Therefore open org.eclipse.ease.releng.target/org.eclipse.ease.releng.target.target and hit 'Set as target platform'.
The whole project can be built by right clicking on org.eclipse.ease.releng / Run As / Maven build. Enter 'clean install' as your goals. After the build process you can find a p2 update site available at org.eclipse.ease.releng.p2/target/repository.
Currently your best chance to provide code is to create a git patch and submit it via bugzilla. Before creating the patch make sure to have your formatter set to the default 'Eclipse built in'.