You can use whatever you like, as long as it outputs the correct html markup. Vanilla html pages, PHP, whatever you like :)
This is an example how to use Razor to create Administrative pages http://www.s-innovations.net/Blog/2013/11/06/Using-Razor-files-inside-the-console-with-Composite-C1-41
This is an example how to use Razor to create Administrative pages http://www.s-innovations.net/Blog/2013/11/06/Using-Razor-files-inside-the-console-with-Composite-C1-41