andLinux uses coLinux, a port of the Linux kernel to Windows which allows andLinux to run almost all Linux applications in Windows, without modifications and comes in two flavors: KDE and XFCE.
Since andLinux installs a full operating system, you'll need to make sure you've got quite a bit of free space on your hard drive. The KDE version eats up more than 4GB of space while the XFCE version takes about 2GB. If all you want to do is run a single Linux application like Amarok, Ardour, or Cinelerra, you might be better off checking out KDE for Windows and waiting for the developers ro port your favorite applications. But if you want to be able to run any Linux application you like without rebooting, andLinux is worth checking out.