Click below to give it a try:

It's still fairly early in development so whatever you do don't use it to backup your patches. It should work on all platforms (Linux/OSX/Windows) and you don't need any other applications/hardware. Just your plug in your XL go to the website ready to go. You'll know if it's connected if you see all your patches come up in the display.
At the moment it's only been populated with the XL Factory patches but hopefully I'll be adding some of my own soon.
If anyone has any problems with the application not working or not connecting to your Microkorg please let me know.