The Nintendo DSi is a dual-screen handheld game console released by Nintendo. The console launched in Japan in 2008, and worldwide in 2009. It is the third iteration of the Nintendo DS, and its primary market rival is Sony's PlayStation Portable (PSP). The fourth iteration, entitled Nintendo DSi XL, is a larger model that launched in Japan on November 21, 2009, and worldwide beginning in March 2010. Development of the DSi began in late 2006, and the handheld was unveiled during an October 2008 Nintendo conference in Tokyo. Consumer demand convinced Nintendo to produce a slimmer handheld with larger screens than the DS Lite. Consequently, Nintendo removed the Game Boy Advance (GBA) cartridge slot to improve portability without sacrificing durability.