David Gurle is a Product Unit Manager at Microsoft. He is responsible for Greenwich, Microsoft's upcoming Instant Messaging solution and Real-time Communications platform. Before joining Microsoft in 1999, David worked with VocalTec Communications as part of the CTO team and Vice President of Business Alliances. While there, he managed VocalTec's technology strategy and lead VocalTec's standards activities on IP Telephony and was editor of major VoIP standards. David also brings to his Product Unit Manager position several years of experience in the European Telecommunications market in job roles ranging from software engineer (Digital Equipment Corporation) and project manager (France Telecom) to technical officer (ETSI). David co-author of the book "IP Telephony, packet-based multimedia communications systems", currently published by Addison-Wesley.