Open Mashups : User generated applications for the masses

The advent of open APIs and rich interfaces led to a new kind of applications called mashups. These applications are characterized by an apparent functionnal simplicity (e.g combining two data sources to provide composite results and display them) but the developpement and deployment of such applications is still very difficult for a non-programmer. Some tools exists to help with the creation of mashups (like Microsoft Popfly, Google Mashup Editor, Yahoo! pipes) but all fail to deliver some features of what’s really needed to make user generated application a reality:

• Clean separation of functionnal (what the application is doing) and non functionnal (e.g look and feel) aspects.
• Independence from devices and execution platforms: no vendor, device or platform locking.
• User friendlyness : no need to be a coder.

Open Mashups provides answers to all these requirements by applying in an open web context rigorous formal techniques from the MDA /MDE (Model Driven Architecture/Engineering) world. We defined a dedicated meta-model that represents an application from a very functionnal and declarative standpoint. This meta-model is the cornerstone of our approach: we provide an easy to use graphical editing environnement to depict application models (both for the GUI and the behavior of the application), and write code generators that produce executable code from these models. This approach allows to hide the complexity to the mashup creator that only needs to understand and manipulate a limited number of concepts, relying on code generator implementors to take care of platform and device adaptation.

The Open Mashups editor is implemented as an Firefox extension that also include a runtime engine to test applications on the fly. This component will soon be provided as an open source software. Code generators are implemented using QVT model transformations.

We’ll demonstrate the end to end toolchain, from application creation to code generation, leading to the same application running on a mobile phone, on a web page or as a desktop widget.