Development for the Integrated Modular Avionics (IMA) platform is complex owing to the variety of equipment, vendors and non-uniform tools. The development should be simplified by a model-based harmonized tool environment by means of an integrated set of tools of different type, origin and purpose. Eclipse's flexible and modular architecture seems adequate as a framework for such a harmonized IMA development environment. This article evaluates how Eclipse could practically be utilized for this purpose. The IMA process and development requirements like concurrency, different process roles, and multiple tools are mapped to the Eclipse framework. In addition, open-source extensions for model-based engineering and application development are integrated in the tools chain. In order to test the performance, openness and compatibility of Eclipse and the tools from the IMA development process, six current and future tools are integrated into a prototype of a common Eclipse instance. The integration covers a common human-machine interface (HMI) and model-based data exchange. The selected tools cover all working areas and tool types expected in the IMA development process. The prototype reveals typical shortcomings of Eclipse as a multi-tool host. The criticality of shortcomings is evaluated, and rules for a harmonized Eclipse environment for IMA development are derived. The research leading to these results has received funding from the European Union Seventh Framework Program (FP7/2007-2013) under SCARLETT grant agreement n° ACP7-GA-2008-211439.