Microsoft Live Messenger released

Press note: Launch of Windows Live Messenger Marks Significant Progress for Microsoft’s Windows Live Era Features:

• Video call.
• Windows Live Call with Verizon Web Calling service.
• Cordless phones designed exclusively for Windows Live Messenger.
• Microsoft LifeCams optimized for Windows Live Messenger.
• Sharing Folders. Now sharing is as easy as dragging and dropping a file. With a new, intuitive user interface, customers can more easily share their files and personal photos with family, friends and colleagues on their Windows Live Messenger Contact List.
• Windows Live Contacts.
• Integration with Windows Live services.

Even localised versions are available for downloading (at least, Spanish version). After installing it we can see a new service is installed (Start Configuration Control Panel Administrative Tasks Services) called: Messenger Sharing USN Journal Reader service. This service is in charge of monitoring USN Journal changes to file system for the directories shared with your msn contacts. These directories are under %USERPROFILE%\Local settings\Program data\Microsoft\Messenger\<your-msn-email> Under that directory you will find a folder called Sharing Folders and a hidden one called SharingMetadata. If you browse through the hidden one you will find another one called DFSR containing ConflictDelete, Deleted, Installing and Staging. For those of you not in the depths of Microsoft Server systems, I will tell you that this directory structure is used also on Windows Server 2003 R2, the newest release of Microsoft servers. One of the main advantages of this new R2 release is the new replication service, called DFS (Distributed File System). Extracted from Distributed File System Technology Center page from Microsoft:

The Distributed File System (DFS) technologies in Windows Server 2003 R2 offer wide area network (WAN)-friendly replication as well as simplified, fault-tolerant access to geographically dispersed files. The two technologies in DFS are as follows:

• DFS Replication. New state-based, multimaster replication engine that is optimized for WAN environments. DFS Replication supports replication scheduling, bandwidth throttling, and a new byte-level compression algorithm known as remote differential compression (RDC).
• DFS Namespaces. Technology that helps administrators group shared folders located on different servers and present them to users as a virtual tree of folders known as a namespace. DFS Namespaces was formerly known as Distributed File System in Windows 2000 Server and Windows Server 2003.

If you are using Windows Server 2003 R2 and want to keep folders synchronized, we recommend using DFS Replication instead of FRS. DFS Replication system in Windows Server 2003 R2 has many benefits over File Replication Service (FRS), including improved management tools, higher performance, and delegated management.

As you can see, it seems that Microsoft is also using their brand-new-fresh-cutting-edge technology for file replication on their new Windows Live Messenger. One of the new features of this file replicating technology is the previously called RDC (Remote Differential Compression), which in summary, only transfers compressed portions of the file that has been modified. If only some chunks of a huge Powerpoint presentation are modified, there is no need to transfer the whole thing again, only the modified portions of the file are compressed and transferred, thus saving time and bandwidth. Since home users do not have the same hight bandwidth as corporate environments have, I'm sure they will be glad to read this. I must congratulate Microsoft for including this new server technology in such an everyday-user product as Microsoft Live Messenger. Note for Live Messenger users: If a shared file is overwritten by both sides at the same time, one of them is selected as looser of the conflict. I suppose that Live Messenger will warn you about this if it ever happens (I haven't tested it wisely). Just for your information, when this happens on a Windows Server 2003 R2, the file that is selected as looser is stored on ConflictAndDeleted. The equivalent for Live Messenger is ConflictDelete.