Methods and apparatus, including computer program products, for generating runtime entities in a visual modeling environment. Input characterizing an application definition at designtime is received, a determination is made as to whether the designtime entity is to be compiled by a first generator or a second generator, and a runtime version of the designtime entity is generated. The application definition can include a designtime entity and a configuration of properties of the designtime entity. The first generator can support compilation of multiple types of designtime entities and the second generator can support compilation of a specific type of designtime entity. The runtime version can be generated with the second generator if the second generator is to be used or, otherwise, generated with the first generator.