Do architects fight like siblings? ‘I want to be tallest, no I want to,” they might bicker. Since the term ‘skyscraper’ was created, there has been a race to the top. When the Burj Khalifa skyscraper opened on Monday, it now holds the title of the World’s tallest building overtaking Taipei 101. Third place will go to the Shanghai World Financial Center, then, the Petronas Towers and the Willis Tower (formally the Sears Tower) will be the 6th tallest skyscraper in the world. Interestingly, most of the recent tallest buildings have been both designed and constructed by just a few companies. The Burj Khalifa was designed by Skidmore, Owings and Merrill, who also designed the Willis Tower in Chicago and 1 World Trade Center, former known as Freedom Tower, which is the main building of the new World Trade Center under construction on the site of the destroyed WTC. The primary builder of the Burj Khalifa is South Korean Samsung Engineering & Construction, who also built the Taipei 101 and Petronas Twin Towers. The ‘tallest structures in the world’ list varies somewhat with any’ tallest buildings in the world’ list. The former includes other man-made structures and towers such as the Canadian CN tower and T.V. towers. The Council on Tall Buildings and Urban Habitat (CTBUH), recently announced a change to its height criteria for judging who wins the tallest prize. Infocus Tech makes souvenir replicas of most of these skyscrapers. Other souvenir versions of the Burj Dubai and Petronas towers are also available. At over 800 meters (2684 feet) and more than 160 stories, the Burj Dubai is a supertall skyscraper under construction in Dubai, United Arab Emirates. The building resembles a bundled tube form - a rounded version similar to the Willis Tower’s multiple connected square segments. Its design is reminiscent of Frank Lloyd Wright's vision for The Illinois, a mile high skyscraper designed for Chicago, but never built. The design of Burj Dubai is derived from patterning systems embodied in Islamic architecture. The design architect Adrian Smith has said the triple-lobed footprint of the building was inspired by the flower Hymenocallis. The tower is composed of three elements arranged around a central core. As the tower rises from the flat desert base, setbacks occur at each element in an upward spiralling pattern, decreasing the cross section of the tower as it reaches toward the sky. There are 26 terraces in the Burj Khalifa. At the top, the central core emerges and is sculpted to form a finishing spire. A Y-shaped floor plan maximizes views of the Persian Gulf. Viewed from above or from the base, the form also evokes the onion domes of Islamic architecture.