Ubuntu's Unity, in contrast, is more of a loosely coupled UI. First and foremost, you can easily replace it with any one of several free alternatives, including KDE, Xfce, LXDE, GNOME 3 Shell, Cinnamon, and MATE.
Also available for Unity are third-party customization tools, including the increasingly popular Ubuntu Tweak, while a raft of look sites are available for myriad Linux interfaces with a variety of themes to change the desktop's appearance.
The rule of thumb with Linux in general and Ubuntu in particular is, if you don't like it, swap in something else. Also worth mentioning is the fact that Ubuntu supports multiple workspaces, essentially letting you run up to four different desktops; Windows 8 Pro does not.
Whereas Windows 8 Pro comes bundled with Microsoft's Internet Explorer 10 browser, Ubuntu comes with a wide assortment of open-source software packages such as Firefox, Thunderbird, LibreOffice, and more, offering both individual and business users a pretty full suite of functionality.
Beyond those bundled programs, both Ubuntu and Windows 8 offer app stores to help users find the additional software they need.
Dating back to 2009, the Ubuntu Software Center now houses more than 40,000 apps, ranging from games to productivity tools to educational resources. In addition, by using Wine or CodeWeaver's CrossOver, you can run Windows programs on top of Linux.