Back in April, I wrote about the initial Live Mesh release, a technology preview, in my Live Mesh Preview. A lot has changed since then. In addition to the expected functionality, performance, and scalability updates, Microsoft has moved Live Mesh out of the technology preview phase and into a full-fledged public beta. And the company has finally opened up Live Mesh to Mac and Windows Mobile clients, dramatically increasing the scope of compatible devices. Given all the improvements, it's time to take another look at Live Mesh.

What is Live Mesh?

Live Mesh is a synchronization platform for files. It transcends--or, more properly, will eventually transcend--the many computing entry points that users now experience, including PC and Mac computers, the Web, and mobile devices. In other words, you can sync--and share--files between PCs, Macs, the Web, and, today, Windows Mobile devices. (More devices are coming, Microsoft says.) And Live Mesh now provides a runtime environment for special Live Mesh applications that will run on all of the supported entry points mentioned above.

This sounds somewhat farfetched, but the Live Mesh described above is very much real and is in fact available today, though the experience isn't yet as full-featured as it will be in the near future. What we have right now is client software for the PC and Mac, and for Windows Mobile, and a Web-based "desktop"--similar to the desktop in Windows--all of which can be used to house folders and files that are automatically synchronized back and forth.

Obviously, each of these entry points, or "devices," as Microsoft awkwardly calls them, has unique storage limitations, so how and what you sync between each entry point is configurable. PCs and Macs have voluminous storage capacities, thanks to the ever-expanding nature of hard drives. The Live Mesh Web-based desktop is currently limited to 5 GB, though it's not hard to imagine a future with more cloud-based storage, including some that is subscription priced. And mobile devices like Windows Mobile smart phones typically have very little storage: 64 MB or so on the device itself and then maybe 2 GB on a storage card if you're lucky. Fortunately, Live Mesh makes it possible to determine which folders are synced to which entry points. And you can now perform peer-to-peer (P2P) synchronization, bypassing the 5 GB limit of the Web desktop and opening up the possibility of massive amounts of data sync.

Live Mesh also supports the notion of sharing files with others. I happen to use Live Mesh solely to sync folders between my many computers, but you can choose to share files and folders with other people via this system as well.

The newest piece is the runtime environment and accompanying developer libraries, which will allow for HTML/Javascript- and Silverlight-based applications to run in any Live Mesh environment. So it's now possible to write applications that run as identically as possible on the Mac, the PC, the Web, and on Windows Mobile phones. In the near future, Live Mesh users will conceivably begin syncing favorite applications alongside the data those applications access. For now, of course, it's more likely that the data that users sync--things like Word Documents, PDF files, and MP3s--will continue requiring native applications on each supported entry point.

There's another unheralded part of the Live Mesh platform that bears some discussion. Live Mesh has an RSS-like notification system, underutilized at the moment, which Live Mesh and the applications that run within it can access and utilize. Currently, this notification system is used only to chart changes to the folders and files you're sharing and syncing, and there is rudimentary support for typing text messages to members of your mesh, sort of a simple form of instant messaging (IM).

During the Live Mesh technology preview, Microsoft exposed a limited set of services. There was the folder sharing and sync functionality that is core to the platform, of course, and over time Microsoft expanded it to include the aforementioned P2P support. And there was remote PC access, similar to the Remote Desktop function in Windows, which, when you think about it, kind of makes sense in the context of Live Mesh's "anywhere/anytime" data access mantra. These services continue into the beta.

How does it relate to Azure?

Looking more broadly at Microsoft's rapidly expanding stable of online offerings, one might naturally wonder how this platform fits into the company's recently announced Windows Azure offering (see my preview). Frankly, it's all a bit confusing. But here's what I know. Microsoft is rearchitecting all of its online services and offerings to exist, technologically and logically, within a single over-reaching platform. Microsoft calls this platform the Azure Services Platform. At the heart of this platform sits Windows Azure, the cloud-based operating system that provides the underlying services and runtime environment for all of Microsoft's online offerings.

On top of Windows Azure, Microsoft is building a number of services that target specific needs and markets. The .NET Services provide building block services for cloud-based applications and services. Microsoft SQL Services provide cloud-based storage. And Live Services provides building block services for user data and application resources. (There are other services built on top of Windows Azure, and Microsoft promises more next year. But let's not confuse matters too much.)

Live Mesh, as you might expect, "lives" within the Live Services layer of the Azure Services Platform and "on top of" Windows Azure. Microsoft describes this relationship as follows: "Live Mesh is a platform experience that is natively integrated with the Live Services component of the Azure Services Platform ? it makes the core functionality of Live Services available to users." In other words, Live Mesh is built using the building block services mentioned above and exposes Live Services functionality to end users. It is the data synchronization portion of Azure.

How does it relate to Windows Live?

When Live Mesh matures out of beta, it will be integrated into Microsoft's consumer-oriented Windows Live family of products and services; expect this to happen in 2009. Windows Live is built on a number of Live Services technologies, including Mesh Services (Live Mesh), Identity Services (Windows Live ID), Directory Services, User-Data Storage Services (Live storage across all Web-based services), Communications and Presence Services (Live Messenger), Search Services (Live Search), and Geospatial Services (Live Search Maps/Virtual Earth).

Given the ever-evolving nature of Microsoft's online services, it comes as no surprise that Live Mesh is currently in a weird holding pattern. Microsoft now offers a service, also in beta, called Windows Live FolderShare, that is very similar to Live Mesh--minus the remote PC access and Live Desktop functionality--but will be renaming this to Windows Live Sync by the time its Wave 3 products and services are finalized in early 2009. The next iteration of Windows Live Sync, however, will be based on Live Mesh. So Live Mesh as we now know it will essentially disappear over time, replaced by Live Sync. That said, I've also been told that the Live Mesh UI will live on, so if you're interested in a clean transition, it may pay to get used to how Live Mesh works today.

What's new in the Live Mesh Beta?

OK, with that bit of preparatory discussion out of the way, let's take a look at what's changed in Live Mesh since it left technology preview mode and entered into beta.

New platform support

The biggest change is that you can now download Live Mesh clients for both Mac OS X and Windows Mobile. Neither, alas, is as full-featured as the Windows version. For example, on Windows you get remote PC access, a feature that is unique to that platform.

The Mac client requires Mac OS X Leopard 10.5 and works much like the PC client. Instead of a tray icon, you get a menu icon, of course, and from there you can configure all of the expected options, like adding existing shared folders to the Mac, creating new folders, and so on.

And shared folders integrate nicely with Apple's less-than-stellar new folder style in Leopard: They look like standard blue-gray folders but with a Live Mesh brand.

Unlike in Windows, where you see a Mesh Bar attached to the right side of every share folder displayed in Explorer, on the Mac, the Mesh Bar floats separately from shared folders. It's unclear what the point of that is--perhaps Microsoft simply couldn't figure out how to make it work--but all the same options are there from the Windows version.

The Windows Mobile experience, as expected, is quite a bit more limited than the PC or Mac clients. You'll see a text-like list of your synced folders and can access a number of choices via a typical Windows Mobile-type Menu. The most important of these is Sync Folder with Mobile, though of course users are going to need to be careful about overloading the tiny memory footprint of their device. Note that Windows Mobile 6.x is required.

In addition to the Windows Mobile client, Microsoft has gone live with a new mobile Web version of the Live Mesh Web site (and Live Desktop), giving users a way to access synced files from almost any modern smart phone. That includes, incidentally, the iPhone, though of course there's currently no way to actually download files to that device locally. On such a device, you can view the news notification list, manage folders in your Live Desktop, and view files such as images, text files, and even Word documents. If the device supports it, you can also download files.

New features and functionality

In addition to broadening the support of Live Mesh, Microsoft has also added a number of small but important new features.

The service now supports the notion of member roles for shared folders. Previously, everyone who had accessed to a Live Mesh folder had "Owner" privileges, similar in scope to admin or root access on a computer system. Now, you can assign other roles to users with which you share folders. These new roles include Contributor (read and write access, but they cannot invite other new users) and Reader (can see the contents of the folder and view but not edit files). A third new role, Creator, is automatically applied to the user who first creates a Live Mesh folder.

Users who access the Live Desktop with Internet Explorer on Windows can now drag and drop files between the PC and the Web, which I'm guessing was one of the top user requests. Previously, you had to install an ActiveX control on IE to upload multiple files to the Live Desktop. And it's even worse with other browsers, where you can only upload one file at a time.

P2P sync has been enhanced in the beta: Now, you can mark folders as P2P only (by excluding the Live Desktop from sync) from your PC, instead of having to do it from the Web only, as before.

There's a lot more. Updates can be automatically installed now. P2P synchronization performance and reliability is much improved. There's a new synchronization status icon that appears in the taskbar when you initialize a large data sync for the first time. Basically, the whole thing has gotten a Windows 7-style fine-tuning.

Developer, developers, developers

It's early yet and things can and will changes, but developers interested in programming Live Mesh applications should check out the recently released Live Framework CTP (Community Technical Preview), which is available from the Live Services Web site.

Final thoughts

Live Mesh has evolved quite nicely over the past several months and while I still think Microsoft could do more to reduce confusion around the future of Live Mesh and Windows Live FolderShare, I suspect those issues will be wrapped up soon. If you've been holding off on checking out Live Mesh, now is the time: It's up and running on Windows PCs, on Macs, on the Web, on Windows Mobile devices, and even on a variety of other Web-enabled mobile devices, and Microsoft has moved quickly to improve functionality, performance, and reliability. The next step, of course, is to see whether the application sync and sharing functionality that's just now been enabled will turn into something wonderful as hoped. Regardless, the future of Live Mesh is bright. This is one of the best services to come out of Redmond in a long, long time. I strongly recommend you check it out.