There are several attempts to investigate partner-ships between software vendors and its stakeholders. The term ecosystem is used to emphasize the aspect of interdependence between the businesses operating in the value chain of the software industry. Messerschmidt and Szyperski introduced an abstract model of the ecosystem's lifecycle in this industry. Using the model as a basis, a survey among 28 enterprise system providers (ERP providers) was conducted to determine specific formations of ecosystems among real world businesses. We investigate the relationships between the actors of the ecosystems and analyze how the different types of ecosystems are operating. The study reveals that several different models occur in relation to specific aspects, such as the size of the ERP provider or additional services provided. The main different models that were figured out as a result of the survey could encourage new approaches to researching value co-creation, including the evaluation of the different software ecosystems.