Over the last few years, the Notte Bianca ('white night') has become something of a tradition among an increasing number of cities across Europe and the rest of the world. For one night in September, the city stays open all night. Public transport keeps going, some shops stay open, along with the museums & galleries, and there are a wide range of cultural events right across the city.
Sadly, 2007 seems to have been the last official Notte Bianca in Rome. Mayor Walter Veltroni, a strong supporter of the arts, is no longer in power, and the administration that followed him withdrew funding from the project. In 2008, La Notte Bianca made do without the official support of the city of Rome, with the different municipi each arranging whatever events they could manage. The same happened to a lesser extent in 2009, with a barbecue here, a show there... nothing on the scale that made La Notte Biana so exciting on previous years.
The official website hasn't been updated since 2007, and is now offline. Although there are isolated local events around the city, La Notte Bianca as it once was is now long gone, and there won't be a Notte Bianca in 2013 - at least, not in Rome.