z3
The Z3 Theorem Prover
Z3 is Microsoft Research's theorem prover that automatically checks whether logical statements and constraints are satisfiable, used in formal verification, compiler analysis, and security research.
Z3 is a theorem prover built by Microsoft Research. A theorem prover is a software tool that can automatically determine whether a logical statement is true, false, or unsatisfiable given a set of constraints. This kind of tool is used in formal verification (checking that a program behaves correctly by reasoning about it mathematically), compiler analysis, security research, and any domain where you need to reason reliably about complex conditions without running the code itself.
The project is released under the MIT license. Pre-built binary files for both stable releases and nightly builds are available on the GitHub releases page, so you do not need to compile the code yourself to start using it. For those who do want to build from source, the README lists several supported build systems: Visual Studio, Makefile, CMake, vcpkg, and Bazel. The library also provides language bindings so it can be called from code written in languages other than C++.
The README itself is mostly a large collection of continuous integration (CI) status badges showing the results of automated tests and builds across many different platforms and configurations, including Windows, Android, WebAssembly, and RISC-V. There are also several automated maintenance workflows listed, such as tools for checking code conventions, tracking academic citations, and processing the issue backlog. These suggest an active and well-maintained project infrastructure.
An introductory guide and background material are available in the repository's wiki and at a dedicated online guide hosted by Microsoft. The README points new users there rather than providing usage examples directly in the file.
Where it fits
- Verify that a program's logic is correct by encoding conditions as Z3 constraints and checking satisfiability.
- Find edge-case bugs in a security protocol by asking Z3 whether a violation is reachable.
- Use Z3 as a solver backend in a custom static analysis tool or compiler optimizer.