A is a useful lightweight tool for UI demonstration, education, and nostalgia, but it cannot replace a virtual machine for actual software testing or productivity. The best simulator for developers was Microsoft’s Visual Studio Simulator (now deprecated), while today’s web-based versions offer a superficial but accessible glimpse into Microsoft’s bold, touch-first era.

It reads: "Windows 81 — Where you always belonged."

Using a simulator today, you will likely experience two emotions:

It’s interesting to see how the "Modern UI" design language has aged. While the transition between Desktop and Metro was jarring back then, looking at it now, the design is actually quite clean and minimalistic compared to the glossy interfaces of Vista/7.