The Walther PPQ is a development of the Walther P99, designed to function much more similarly to a Glock. While the P99 was and has been enormously successfully with military and law enforcement units all over the world, it has been noticeably less popular here in the United States. In the late 2000s, Walther developed the Walther P99Q pistol, which as a single action only trigger much like a Glock or Smith & Wesson M&P (only the trigger pull is much lighter and crisper).
In 2011 in the USA, the P99Q was rebranded as the PPQ and released. It was later evolved in 2013 as the M2 model with a push button magazine release that American shooters typically prefer. The PPQ has become Walther’s flagship model for the American market, with a countless number of variants released. It is currently available in the .22 LR, 9mm Luger, .40 S&W, and .45 ACP calibers.