Although EWG can be used without the GOBO tools geant and gexace it is highly recommended to use them. EWG comes with reusable geant-scripts that help you create a cross-eiffel-compiler, cross-c-compiler and cross-platform automated build process.
A good way to get started with the build process is to go to the simple or callback example and run geant with the --verbose option.
TODO: Documentation for build process