It seems that web based applications can accomplish today the most extensive and complex tasks that were possible before only by locally installed software. One aspect that has not been addressed by either Microsoft IE or Firewfox, the leading web browsing software, is working offline. Although Microsoft has mentioned it in the past under the hat of Smart Client architecture still current products do not show any sign of support.
Offline capability is something not trivial for browsers to implement due to the unique needs each application has and the inability of applying a generic approach to support these different needs.
Once implemented it will remove many barriers to network computing and will enable full productivity over the web. R&D and IT maintenance costs will be lower as well as removal or at least weakening of vendor lock-in with installed software. This futuristic scenario is the dream of many vendors that wish to play and win based on quality of software and features and not on sunk cost decisions.
A hybrid solution for this problem can be in the way of downloading a reducted copy of the web application locally (Can be downloaded by the browser as part of current "work offline" implementation) and when the user is disconnected from the net, the web browser communicates with the local version of the application that has limited but complete functionality. The offline "copy" of the application will be developed by the web application developers. Once connected back to the net, the browser can transmit this changes to the site as part of the startup phase (Should be implemented in a secure manner of course) where inconsistencies and confirmation can be displayed to the connected user.
This can be implemented easily within current browser frameworks and without many incompatibility issues.
If to be done by Firefox, who tend to implement new capabilities faster, a very strong! competitive edge will emerge.