Dafny
5.7#26 in formal verification toolsLinuxmacOSSelf-hostedWindows
VisitDafny vs Lean
What both publish
| Fact | Dafny | Lean |
|---|---|---|
| Learning resources | The Dafny documentation links to a getting-started tutorial, reference manual, FAQs, error explanations, verification optimization guide, style guide, and examples. | The learning page links to textbooks, tutorials, interactive games, core documentation, and an API reference. |
| License | The Dafny software is licensed under the MIT License. | Lean is released under the Apache 2.0 license, which the documentation describes as allowing others to use and extend the code and mathematical libraries freely. |
| Platforms | Installation instructions cover Windows, Linux, and macOS; the project repository also lists binary downloads for FreeBSD. | The reference lists Linux, macOS, and Windows among Lean’s supported platforms, with Tier 1 binary releases available through elan. |
| Support | The project directs users to its Zulip channel for questions and GitHub for issue reports. | The Lean Community Zulip is described as the central hub for questions and collaboration, and Lean FRO hosts weekly technical office hours. |
| What it does | Dafny is a verification-aware programming language with native support for recording specifications and a static program verifier that checks code against them. | Lean is an open-source programming language and proof assistant for writing correct, maintainable, formally verified code. |
Dafny plans
No prices published.
Lean plans
- Lean 4Free
Pick Dafny if…
Dafny may suit developers who want to verify code against explicit specifications, as well as people using it for teaching or research. It also supports industrial use and offers Visual Studio Code and Emacs guidance.
Pick Lean if…
Lean suits programmers, theorem provers, and mathematicians working with formalization, proof checking, or software verification. Its general coding capability and browser version may also suit users exploring Lean before choosing a local setup.