Why does Eclipse automatically add the appcompat v7 library whenever it creates a project?

Why does Eclipse automatically add the appcompat v7 library whenever it creates a new project? I just want to create MainActivity, which simply inherits Activity. Eclipse automatically creates a project that supports the action bar. Is it possible to make a project without the appcompat library?

I update the ADT every time, so it's the latest version The operating system is a Windows 7 64-bit environment.