Microsoft is acquiring Swiss software company Media-Streams with the aim of adding voice-over-IP (VoIP) functions to its Office products, it revealed today.

It did not reveal what it will pay for acquire the Zurich-based company. The technology it gains as a result of the deal will help it add VoIP to the Office Live platform, which already supports real-time communications through instant messaging.

VoIP is big business, not idle chatter

VoIP is big business as evinced by eBay's $2.6 billion acquisition of Skype Technologies last month. Its image has been changing from something that consumers use to make cheap, low-quality voice calls via their PCs, to a more stable technology suitable for professional applications such as business.

"VoIP is exploding," Bill Gates, Microsoft's chairman and chief software architect has said: "We want to enable the software richness on the PC to connect out to traditional PBXes."

The company has formed tie-ups with AT&T, Amdocs and Sylantro Systems to work on various VoIP systems. In August it acquired Teleo, a developer of services and technology that allow users to make and receive voice phone calls on their PCs via the Internet. A month later Microsoft said it planned to work with Qwest Communications to provide VoIP services to SMBs.

Gupta's gumption will become part of Microsoft's real time collaboration business group, which is led by Microsoft corporate vice president Anoop Gupta.

Microsoft will continue to offer's software on a stand-alone basis and existing customers should see no immediate impact from the acquisition.