**Keil MDK**
 
Keil MDK is a comprehensive software development environment for ARM-based microcontrollers, widely used for firmware simulation and debugging.
  - Pros: Extensive library support, integrated debugging tools, and a broad range of device support.
 
  - Cons: Can be expensive, steep learning curve for beginners.
 
  - Cost: For personal use, a free version with limited functionality is available. Commercial licenses cost upwards of $3,000 depending on features.
 
  - Relevance: Highly relevant for ARM Cortex-M developers.
 
  - Devices Supported: ARM Cortex-M microcontrollers from manufacturers like STMicroelectronics, NXP, and more.