A few years have passed since Canonical first unveiled Ubuntu One (U1), a commercial cloud synchronization service designed to integrate with the company's Linux distribution. Last week, Canonical introduced a new client application that brings support for Ubuntu One file synchronization to the Windows platform.

When we first reviewed U1 back in 2009, we highlighted the lack of cross-platform compatibility as one of the service's most significant weaknesses compared to popular alternatives like Dropbox. That might seem like an odd criticism to direct against a synchronization service created by a Linux vendor, but it's worth noting many Linux users rely on other operating systems—whether it's through dual-booting, virtualization, or an additional computer.

Canonical found that there was considerable demand for Windows support among existing users of the U1 service. The new Windows-compatible client addresses that need and might also help boost the appeal of U1 outside of the Ubuntu enthusiast community.

"We have long received feedback from Ubuntu users regarding their evolving needs to manage all their content from a single, secure place across multiple platforms and devices," the U1 team wrote in a blog entry about the new client. "We've looked at many use cases, the most common being the Ubuntu user who is using more than one device or OS. Many people have to work in Windows or Mac environments, even if they prefer to use Ubuntu as their home desktop or OS of choice."

A beta version of the client was first introduced last year, but the software is finally mature and ready for widespread use—it is available for download from the Ubuntu One website.

We tried out the new client on the recent Windows 8 developer preview to see it in action. Installation was relatively painless—Canonical provides a stand-alone installer (an executable, not an MSI) that fully automates the process. After you finish installing the software, you can run it from the start menu or a desktop icon.

The first time that the U1 client runs, it will prompt you to set up your U1 account. After you put in your credentials, the configuration process will ask you to specify what folders you want to sync. It will automatically put the standard Ubuntu One folder in your user directory, but you can also optionally add your documents folder or whatever else you want.

When the setup process is complete, the application will display your U1 dashboard. It tells you what percentage of your storage capacity you are using and the current synchronization status. It also has a handy view of your synced folders so that you can conveniently toggle which ones you want to sync. You can also use the dashboard to throttle the software's bandwidth consumption and see the devices that you have connected to the service.

Users of the Ubuntu One music store can optionally configure the U1 client to sync their purchased songs to the filesystem. U1 exposes the purchased music folder as a cloud folder in the list of directories that are available for synchronization. All you have to do is click the checkbox next to the folder in the dashboard.

During my tests of the new client, file synchronization worked as expected. Files that I added or modified in the synced folder on Windows were properly replicated to my Linux desktop computer.

The client itself appears to have been developed with Python and Qt, much like Canonical's Bazaar client for Windows. For users who want to peek inside, the source code is available from the project's version control repository on Launchpad.

Ubuntu One has expanded considerably since its initial debut. Mobile clients, support for music streaming, and a number of other features have helped to make it more competitive with its more well-known rivals. The Windows client is another good step in the right direction, but there are still some feature gaps, such as the lack of a Mac OS X client. U1 hasn't succeeded in displacing Dropbox as my preferred synchronization solution yet, but it's starting to look a lot more compelling than it has.