Microsoft Azure CTO Uses AI to Port 20-Year-Old ZoomIt Tool to macOS in Two Days
Microsoft Azure CTO Mark Russinovich used generative AI to port ZoomIt, a 20-year-old Windows utility, to macOS in just two days. Using around 12 prompts, the AI generated core functionality in less than 30 minutes and achieved approximately 90% feature parity over the weekend. This real-world case study demonstrates how AI code generation can dramatically accelerate cross-platform software migration and handle complex platform-specific APIs. It highlights how experienced software engineers can leverage LLMs to quickly bypass the learning curve of unfamiliar operating system frameworks. The AI handled platform-specific mechanics like macOS UI guidelines, system permissions, screen capture, and global key hooks while adding back features like DemoType and Demo Mirror. ZoomIt for Mac is now free and open-source, available via Homebrew or GitHub for macOS 14 Sonoma or higher.
## BACKGROUND
ZoomIt is a popular screen zoom, annotation, and recording utility originally developed by Mark Russinovich as part of the Sysinternals suite for Windows. Porting legacy desktop applications across operating systems traditionally requires rewriting native APIs for screen capture, user input, and window rendering from scratch.