The Windows Live Messenger Library 3.0, that is included in the latest release of the Messenger Web Toolkit, introduces a few user experience improvements. The previous versions of the Messenger Library used session based messaging for IM conversations. As with any session based protocol there was a noticeable delay between the session initiation and the time the users could actually send messages. The newer version uses a new messaging feature that makes it possible to send messages without the need for creating a session.
Additionally, the Messenger Library’s polling mechanism to fetch messages from Messenger has also been improved. The previous version used a single channel to make HTTP requests but in the new version the polls happen on two different channels. This means that in any given time there is at least one ready connection to Messenger.
In short this means a great integrated IM experience for the users of your web application with the performance on par with desktop applications. By simply migrating your application from 2.5 to 3.0, you will see these improvements instantly. As always, your continued feedback is highly appreciated.
Software Design Engineer
Messenger Platform Team