The amount of software developed for educational purposes has steadily increased over the last years. A growing subset of these developments is intended for use in mobile devices. This puts special requirements on implementations that need to be overcome before mobile learning can be more widely adopted. In this paper we investigate how educational software development community can be encouraged to develop more sustainable and interoperable applications. This investigation is done by first surveying the different aspects of reuse to give a background and motivation. Then, a survey of current practice is performed. The survey provides initial insights into how reuse and interoperability is used in authentic practice. Findings indicate that there is much to be done in terms of interoperability and reuse for mobile learning applications. The result of this study confirms that two of the main challenges that developer of educational software in general and mobile learning in particular face is interoperability and reuse. Finally, some directions to overcome these challenges are proposed.