Alloy Analyzer vs Z3

Alloy Analyzer is a free model-checking tool for describing systems in the Alloy language and exploring the structures those descriptions permit. It searches for structures that satisfy constraints and for counterexamples to properties. Models can represent collections of structures that change over time, including security configurations and switching network topologies. The Analyzer presents results graphically, with appearance options that can be tailored to a domain. Alloy 6 adds mutable state, temporal logic, and temporal model checking; that checking requires NuSMV or nuXmv to be installed and available in PATH. The self-contained executable includes the Pardinus/Kodkod model finder, SAT solvers, the standard Alloy library, tutorial examples, and source code. The same JAR can be used as an API in other applications. Sterling adds a web-based visualizer with graph and table views, customizable and extendable with JavaScript. Alloy is self-hosted, supports Linux, macOS, Windows, and API use, and is maintained by volunteers.

Z3 is a theorem prover and satisfiability modulo theories (SMT) solver used in software verification and analysis. SMT-LIB2 is its default input format, and it supports the SMT-LIB format. The project documents bindings or APIs for C, C++, .NET, Java, Go, OCaml, Python, Julia, and JavaScript/TypeScript. Z3 can be built with CMake, vcpkg, or Bazel, and the repository links to pre-built binaries for stable and nightly releases. A project wiki also links to a page for trying Z3 in a browser. It supports proof artifacts and counterexamples, and listed input languages include SMT-LIB2, Rust, Smalltalk, and several of the languages with documented APIs. Z3 is MIT licensed, with downloads and source code available at no charge. Python is required to build it; additional toolchains are needed for Java, .NET, OCaml, and Julia APIs. The README says MSVC builds enable Control Flow Guard and Address Space Layout Randomization by default.