Microsoft Aims to Replace C/C++ with Rust by 2030

Microsoft has embarked on an ambitious program to translate its extensive C and C++ codebase into Rust by 2030. This initiative, announced by Microsoft distinguished engineer Galen Hunt, aims to enhance security and reliability across Windows, Azure, and other Microsoft products.

Background

Who: The initiative was publicly announced by Galen Hunt and involves Microsoft’s engineering teams for Windows, Azure, and security.
What: A program to replace C/C++ code with Rust, leveraging AI and algorithmic tooling.
When: Target completion by 2030, with public reporting in late 2025.
Where: Applies to Microsoft’s internal codebases.
Why: To address memory-corruption vulnerabilities and improve security.
How: Using AI agents, code-graph algorithms, and human review.

Key Features of Microsoft’s Approach

AI plus Algorithms: Combines algorithmic code-graph analysis with AI agents for code translation.
Scale Ambition: Aims for a high throughput of code translation, targeting “1 engineer, 1 month, 1 million lines of code.”
Incremental Adoption: Expands existing efforts to move subsystems to Rust.
Safety Rationale: Rust offers stronger compile-time guarantees against memory errors.

Technical and Organizational Challenges

Legacy Complexity: Decades of C/C++ code with tight dependencies complicate translation.
Semantic Fidelity and Correctness: Ensuring correct behavior and performance in translations.
Tooling and Verification: Requires robust testing and verification practices.
Ecosystem and Developer Skills: Training engineers and adapting build systems.

Industry Reaction and Implications

Security and Reliability Gains: Potential reduction in memory-corruption bugs.
Demonstration Effect: Could accelerate Rust adoption across other organizations.
Skepticism and Realism: Concerns about the enormity of the task and need for careful review.
Commercial and Competitive Angle: Reinforces Microsoft’s strategy of integrating AI into developer tooling.

Context and Likely Trajectory

Microsoft has been exploring Rust and AI-assisted code work for several years. The current program formalizes these efforts, focusing on translating security-sensitive components first. Progress metrics and demonstrator projects are expected to appear, with broader migration tooling published over time.