(It does seem to run in Firefox 18.0.2 on Windows 7 (64-bit) for me.)
SkyDrive is a cloud storage service from Microsoft. It is commonly used for picture sharing by Windows Live Hotmail users. There is a Windows application to integrate SkyDrive into your system which you can download here: http://windows.microsoft.com/en-US/sk.../download. That probably runs independently of your browsers, communicating with Microsoft directly.