Sunday, November 27, 2011

Cocoon – A new framework for Windows 8 Development

Regular followers of my blog will know that over the last year I have been discussing a framework that I introduced for Windows Phone 7 development named Chrysalis ( Whilst not a Model-View-ViewModel (MVVM) framework itself, allowing the use of your preferred framework for this purpose, it was designed to enable view models to interact with the phone lifecycle and hardware in a simple and natural manner.

Following the announcement of the Windows 8 Metro-style application programming model at Microsoft’s //build conference, it became clear that many of the same challenges would present themselves for Windows 8 applications.

The Cocoon Framework

To assist with Windows 8 Metro-style applications I would like to announce the Cocoon framework ( This aims to build on top of the learning from the Chrysalis project to provide a simple way to develop Metro-style applications in a manner that fits naturally with the MVVM design pattern.

It is likely that many Metro-style apps will be connected applications, downloading data from across the internet in response to user navigation. Modern applications are expected to do this in a seamless manner, retrieving data on demand and populating the user interface in response. In some ways this is at odds with the web API programming model that is based upon individual request-response calls, with paging used to retrieve large datasets. One of the first targets of the Cocoon framework is to simplify this process – bridging the world of stateless web API calls, with the “fast and fluid” interfaces expected by users.

Cocoon Framework Development

Since Windows 8 is currently at an early stage, it is anticipated that the Cocoon framework will evolve alongside further releases. If functionality is introduced in the platform that duplicates that within the Cocoon framework, efforts will be made to migrate to the platform support whenever possible.

It is an exciting time for Windows developers, with the upcoming release of Windows 8 ushering in a new ecosystem of applications. The Cocoon framework will allow you to focus on your individual business logic, whilst ensuring that the user experience fully supports the richness of the platform.


To conclude, the first source-code drops of the Cocoon framework are freely available on CodePlex ( As the project evolves, new functionality will be explained on this blog so stay tuned.