Boogie vs Lean
Boogie
github.com
Lean
lean-lang.orgSide by side
| Figure | Boogie | Lean |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | — | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Formal Verification Tools | 8.1 (#7) | 8.6 (#2) |
| License | Boogie 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. |
| Support | The project directs users to its GitHub issue tracker to ask questions and report issues. | The Lean Community Zulip is described as the central hub for questions and collaboration, and Lean FRO hosts weekly technical office hours. |
Plans
In their own words
Boogie
Boogie is a modeling language and tool for building program verifiers for other languages. It accepts Boogie language input, can optionally infer invariants, and generates verification conditions for an SMT solver. Z3 is the default solver; CVC5 and Yices2 support is experimental. The Civl extension lets users model concurrent and distributed systems. Boogie is self-hosted and distributed as a.NET global tool through NuGet. It requires.NET and a supported SMT solver, and the NuGet listing identifies version 3.5.7 as targeting.NET 8.0 or higher. The project uses the MIT License and is free at free. The repository names VCC and HAVOC for C, along with Dafny, Chalice, Spec#, and Move verifiers, as projects built on Boogie. Yices2 has a stated constraint: it works for unquantified fragments such as arrays, arithmetic, and bitvectors, but not for quantifiers, generalized arrays, or datatypes. Users can ask questions or report issues through the project issue tracker, and contributions are accepted through pull requests.
Lean
Lean is an open-source programming language and proof assistant for formalizing mathematics, verifying software, and writing general code. Its minimal trusted kernel checks proofs, and the project describes it as supporting correctness in mathematical, software, and hardware verification. Lean includes the Grind tool for automating some pattern matching, case analysis, and systems of linear inequalities; metaprogramming lets users add notation and proof automation. Projects are managed with Lake, the package manager bundled with Lean. Mathlib is a community-driven library with over a million lines spanning areas including algebra, analysis, topology, probability, and computer science. The recommended setup uses VS Code with the Lean 4 extension for syntax highlighting and code completion, while Neovim with lean.nvim is also well-supported. Lean runs on Linux, macOS, and Windows, and Lean4Web lets users run code in a browser. The software is free under the Apache 2.0 license. Learning resources include textbooks, tutorials, interactive games, documentation, and an API reference.