Reports indicate that Maxis is poised to announce SimCity 5, the first mainline entry in its city-building simulation in nine years, during GDC next week. According to GameSpot, Maxis executive Lucy Bradshaw has confirmed to German print publication GameStar that a new SimCity title is now in development, and is due to release in 2013. In addition, GameSpot says that the new title will run on a brand-new graphics engine, dubbed GlassBox. Adding credibility to that report, Maxis owner Electronic Arts is scheduled to host a sponsored session titled "Inside the GlassBox" at next week's Game Developers Conference. While the description for the Wednesday morning GDC session, presented by Maxis and EA's Ocean Quigley, Andrew Willmott, and Dan Moskowitz, does not directly mention SimCity, it says that the GlassBox engine was "built from the ground up to power the next entry in one of [EA's] most beloved franchises." A separate EA Game Changers event being held off site during GDC is billed as discussing the "power to change a world together", and its first announced speakers include Oscar-winning film director David Guggenheim (The Inconvenient Truth) and Charity Water founder Scott Harrison. Since the release of the mainline SimCity 4 in 2003, the city management series has until now only seen spinoff titles such as SimCity Societies, as well as a number of ports to handhelds, browsers, and mobile devices. Gamasutra has contacted Electronic Arts for further comment, but has not heard back as of press time. (Image credit: Spanish gaming site Jirbo)