Hands on: Mesh takes Silverlight offline

Late last year, Microsoft unveiled various pieces of its cloud computing strategy under the overall name Windows Azure. One of those pieces is the Live Framework, which combines with Silverlight to create a category of applications that blur the boundaries between web and desktop. What follows is a hands-on example with some interesting features.

The application runs either in the browser or on the desktop. It makes no difference where it runs; it has access to the same data and services.

It runs online and offline. Within reason, it works the same. Data modified offline is automatically synchronised when next connected.

If the application is updated, all instances on all computers are automatically updated.
It should run on the Mac as well as Windows, and maybe on Linux one day, although in our tests even the Mac version failed.

When running on the desktop, it uses the Silverlight runtime, rather like the way AIR (Adobe Integrated Runtime) uses Flash for desktop apps.

All this is promising, but it is early days for Microsoft’s effort. The current Live Framework CTP (Community Tech Preview) is buggy and under-documented. Getting some of the information means sitting through online videos or trawling forums. Access requires a developer token – issued in limited numbers – so consider this a peek into the possible future of Windows cloud applications, rather than something useful now.

Getting started
This example is based on a Live Framework CTP, so the details are subject to change, but it gives a good idea of what’s involved. The starting point is to sign up for the developer preview of Live Mesh.

If Microsoft allows, you will get a developer token that lets you create apps. Next, you need several pieces installed, in this order: Visual Studio 2008 with the Silverlight 2.0 SDK; the Live Framework SDK (a zip file which you need to expand into your Program Files\Microsoft SDKs folder); a setup file called LiveFrameworkTools.msi (a separate download), which modifies Visual Studio to enable Mesh projects; and the Live Framework Client, which you will need if you want to try out desktop applications.

This Live Framework Client is an updated version of the existing Live Mesh that you may have played with. When first released, Live Mesh did little more than synchronise files. This new version supports applications as well. Unfortunately, you cannot have the two side by side, and they do not work against the same data. This might mean using a spare or virtual PC for development. You do not have to use Silverlight for Mesh applications – there are a variety of other options including plain web applications – but it is a particularly interesting possibility.