Let’s look at the numbers. Visual Studio (the Community edition) is free. The Arduino IDE is free. The GCC compiler (which Arduino uses) is open-source and free.
An article about license keys wouldn't be complete without touching on the elephant in the room: keygens and piracy. Visual Micro License Key
: Offers a 45-day free trial with full functionality. Let’s look at the numbers
Visual Micro provides a powerful Arduino-compatible IDE extension for Visual Studio, utilizing a license key to unlock full features beyond its initial evaluation period. Key Licensing Facts Visual Micro License Key