for all consoles. The PS3 also has Blu-ray Disc compatibility. The Wii implemented an innovative game controller that features full motion sensitivity and is wielded like a remote, with limited button interaction. In response, the PS3 introduced tilt-sensitive functionality with its controllers. The Wii's motion sensitive controls and focus on family-friendly games, while alienating some hardcore gamers, helped the Wii to become the best-selling console of the seventh-generation. The high price of the PS3 had initially caused slow sales, but numerous price cuts and efforts to bring feature-parity between it and Xbox 360 were made in the years following. It was generally successful as the PlayStation 3 steadily increased in popularity, resulting in lifetime sales to be nearly equal to that of the Xbox 360. Nintendo continued to dominate the handheld console market with the release of the dual-screen Nintendo DS in 2004. One of the screens is a touchscreen. The PlayStation Portable, released in 2005 by Sony, was the first serious competitor to Nintendo's handheld video game consoles and is by far the best-selling non-Nintendo handheld. History An evolving industry Early on in the decade, the video games world was shaken up over two major stories that dominated the headlines: Sega was pulling out of the console war and that Microsoft was entering the market. Sega stated that the poor performance of the Sega Dreamcast and Sega Saturn lines contributed to their decision. The company returned to third party publishing for the remaining consoles. Microsoft officially debuted their Xbox console at the Game Developers Conference in 2000 after much speculation. After the release of the Xbox and PlayStation 2, a noticeable trend was to push video game consoles into media centers and offer more features than just playing games. Nintendo was slow to react and released the Gamecube in 2001 without many of the exotic features seen in other consoles. Instead, Nintendo was focusing on improving the gameplay experience, as well as preparing its new innovative controller to be released in 2006. Backward compatibility also became a staple feature to gaming in this decade. The PlayStation 2 was the first major system to allow for backward compatibility to a preceding console. Copyright infringement became a big concern to game developers and many companies tried experimenting with ways to combat the growing problem, especially among PC games. Some companies required registration through the use of a product key. In one