From the press release:

Today, Microsoft Corp. and Linux platform provider Xandros announced a messaging protocol license and collaboration agreement that will enhance the interoperability of Scalix e-mail servers with various mobile and personal computer-based e-mail applications that utilize Microsoft® e-mail protocols. This agreement expands on the ongoing Microsoft-Xandros collaboration.

Both companies' commitment to protocol licensing and technical cooperation will help to provide more e-mail choices and value. By continuing their focus on mixed-source solutions, Xandros and Microsoft are demonstrating how protocol-level collaboration can benefit customers who rely on a mix of Windows®-based and Linux systems.

By licensing the Microsoft Exchange ActiveSync® protocol and the Outlook® Exchange Transport Protocol, Scalix Mail Servers can now synchronize data over wireless networks with Microsoft Exchange Server as well as various e-mail clients that use these and other Microsoft protocols.