The next version of Messenger will be released as an open beta this summer, and offers three principal improvements.

"Hundreds of millions of people use Messenger every day, and we heard loud and clear that they wanted to do more in their conversations," said Piero Sierra and Jeff Kunins, group program managers for Windows Live Messenger and Social at Microsoft, in a blog post.

"We focused on improving the personal interactions with your close friends, so that you can continue to connect in even richer ways with the people you care about most."

In order to let users stay in touch with contacts, Microsoft will bring information from other sources into the Messenger app, and will link to sites including Facebook, LinkedIn and MySpace.

This means that Facebook users will be able to see contacts' new photos, videos and other information from the desktop. Microsoft said that it will add more partner sites shortly.

Finally, and reflecting the increasing mobility of web users, Microsoft has built Messenger directly into Hotmail, much like Google does with its own chat application and Gmail.

Support for SMS has also been increased, and Microsoft has developed new Messenger apps for mobile phones.

Messenger Connect, meanwhile, gathers together a range of APIs, including Windows Live ID, Contacts and a web toolkit.