Can Browser applications go offline?

an offline web application helps in using the web application during the brief periods of downtime you might experience. it should have the benefits of a web application when you connect again and it would be nice if it can sync the offline operations once it comes online.Microsoft Outlook is a desktop application that provides this switching between offline to online mode. Can there be a Browser application doing the same?

This effectively means an application which is independent of operating system say windows or non-windows. There was one problem where the customer was looking for an application that needs to be accessed from various locations and also offline. I was initially wondering whether i need to go to Windows Forms based applications that can go online too. This restricts my solution to windows. Then I was checking at WPF which promises one code and multiple deployments, but was not proving what i want. when I also thought of building a java Web start application that can be build. But most of them are not focused on building applications that can go offline.

I  goggled and found Google gears and Acrobat AIR are providing the ability to have browser application that goes offline. i also the web application http://www.rememberthemilk.com/. is build on Google Gears and can be used offline.

I find from blogs that Microsoft Silverlight is not supporting browser applications go offline. Microsoft has introduced their synchronization platform known as the Microsoft Sync Framework.   This framework allows developers to create offline applications, devices and services that will integrate any type of data with any application