Microsoft debuted its original big, black, and green Xbox in North America on November 15, 2001. It retailed for $300 and launched within the sixth generation of consoles, which made it the first major gaming system to be created by an American company since the Atari Jaguar.

Prior to its launch, Microsoft's major gaming efforts had been focused on the PC, where its Windows operating system held a monopoly on the market. Arguably the closest the Redmond, Washington-based company had gotten to launching a console was when it developed a custom version of Windows CE for the Sega Dreamcast that supported a version of its DirectX API.

After seeing how Sony's console business was detracting from PC game sales and fearing that the rival company would own the living room with the PlayStation 2, Microsoft decided to release its own system to compete. An early prototype was put together by Microsoft engineers as a side project using Dell laptop parts. Microsoft decided to invest and iterate on this design, which eventually paved the way for the Xbox to use the PC's x86 architecture, which was rare for a console at the time. The operating system was based on Windows' architectural kernel. The system was originally going to be called the DirectX Box, since it used the company's DirectX API, but was shortened to Xbox after focus groups thought it sounded better.

The console was equipped with a 32-bit Intel Celeron/Pentium III hybrid CPU clocked at 733MHz. It had 64MB of DDR SDRAM clocked at 200MHz set up in a dual-channel configuration. For its GPU, the Xbox used a custom chip from Nvidia based on the company's GeForce 3 line of graphics cards, and was clocked at 233MHz. The GPU supported Microsoft's DirectX 8 API and was capable of delivering 7.3 gigaflops of performance. Though it supported 32MB memory cards, it also came with an 8GB hard drive, which was a costly investment for the company at the time. This made it the first console to include a built-in HDD.

While developers generally agree that the Xbox was more powerful than the competing GameCube and PlayStation 2, few third-party ports took advantage of the extra processing power. It ended up selling over 24 million units, which allowed it to edge out Nintendo's system. Though it came in second that generation and established a reputation for the company in the console space, it was sold at a loss, and greatly fell short of matching the sales of the PS2, which sold over 155 million units. Despite major efforts by Microsoft, the console struggled in Japan, with some figures estimating it sold roughly half a million systems. Compared to the competition, the Xbox became a haven for more western games and first-person shooters, the latter of which were relatively rare on consoles.

Halo was a surprise hit for Microsoft and catapulted the system to the main-stage. The company had acquired developer Bungie for the game and the Xbox-launch exclusive raised the bar for first-person shooters on consoles. It also became a fan-favorite at local LAN parties thanks in part to the fact that it supported up to 16 players: Four consoles with four attached controllers could sync up over their Ethernet ports. The Xbox was the first console to support a broadband Ethernet port, and it paved the way for Xbox Live, Microsoft's subscription-based online gaming service. Xbox Live was able to grow and ride the success of Halo 2, which sold over eight million units. The online service itself peaked that generation with around 20 million users.

Competed Against: Sega Dreamcast, Sony PlayStation 2, Nintendo GameCube

Notable Games: Burnout 3: Takedown, Conker Live and Reloaded, Dead or Alive 3, Fable, Forza Motorsport, Halo: Combat Evolved, Halo 2, MechAssault, Ninja Gaiden, Panzer Dragoon Orta, Project Gotham Racing, Star Wars: Knights of the Old Republic, The Elder Scrolls: Morrowind, Tom Clancy's Splinter Cell