Alloy Analyzer vs SPIN

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.

SPIN is a free, self-hosted model-checking tool for analyzing the logical consistency of asynchronous systems, including distributed software and communication protocols. Systems are specified in Promela, which represents asynchronous processes, nondeterministic choices, loops, and local or global variables. Models can state correctness requirements, including linear temporal logic. SPIN supports interactive, guided, and random simulations of execution. For verification, it generates a C program for exhaustive or approximate checking of those requirements. Its product description lists detection of deadlocks, race conditions, incomplete specifications, and unjustified assumptions about process speeds. Partial order reduction optimizes verification runs, while the site provides guidance for multicore depth-first and breadth-first algorithms and swarm methods for large state spaces. SPIN runs on Linux, macOS, and Windows, as well as other listed systems. From version 6.4.5, its code, sources, and executables use the BSD 3-Clause license. Verification requires a working C compiler and preprocessor. The optional iSpin graphical interface is written in Tcl/Tk and requires Tcl/Tk.