So there was a lot of chatter online on whether the windows mobile 7 platform, soon to be released will support multi-tasking. The answer is yes and no.
Multi-tasking is a feature by virtue of which multiple applications can run on the device simultaneously sharing the platform compueting and other resources. For example, a user may wish to load a webpage in the browser application, while they read their email in the mail application.
The answer to whether the OS supports multi-tasking, is yes - in that it does natively support running multiple applications simultaneously. This will be seen out of the box for applications that ship with the phones. For example you will be able to use your mail application while a webpage is loading in the browser or be able to listen to music or watch videos, while browsing the web.
However, Microsoft is being careful about how the multitasking features are exposed for third party applications that don't ship out of the box with the phone. This is necessary for a number of reasons. If a platform allows all 3rd party code to run in the background, the users may face degraded performance of the app in the foreground, depending on what resources are being hogged by the application that is running in the background. Also badly written applications can cause wasteful usage of the platform resources in the background thereby causing unpredictable battery life performance etc.
The platform does allow the running 3rd party applications a grace period after the user has switched away from the application, during which the application may save state, handle closing events and do some background operations before it is shut down. All written applications will be able to hook onto this event. The platform also allows push notifications to be sent for applications to their users. The users will see these notifications, even if they are not using the applications and can then go into the applications to do more.
Another feature that is exposed to 3rd party applications is that they recieve notifications of system events such as for example a call coming in while the application is being used. Because of this, the users can switch away from the application, take the phone call and then return to the application and continue using it in the state that they left it.