Mashups can provide a powerful way of combining functionality to meet particular use cases. But to date it has been difficult to move mashups between platforms. The Omelette project has developed Open Mashup Description Language (OMDL) as a simple way to export mashups consisting of pages, layouts and widgets for use in other applications. For example, OMDL can be used to export a profile page or a workspace from a portal or social network and import it into another. The specification provides users with a way to share widget-based page layouts, such as dashboards, so that they can be readily imported and reused elsewhere. This is useful for organisations that have multiple platforms, or where there are multiple servers running portals. OMDL provides a way for users to create mashup "templates" that can be shared with other users and across platforms. OMDL describes the structure of a page that includes widgets. Widgets can the W3C Packaged Web Apps, or OpenSocial Gadgets, or any other kind of widget supported by platforms. Where a specific widget format isn't supported, platforms can default to a native widget that performs a similar function.
OMDL has been implemented in Apache Rave and in Moodle. If you are interested in learning more about this work, please visit http://omdl.org/community.html and join the Google group dedicated to the specification. On the site you will also find resources about the specification and its use.