PRISM

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What PRISM is

PRISM is a probabilistic model checker for formal modelling and analysis of systems with random or probabilistic behaviour. It supports discrete-time and continuous-time Markov chains, Markov decision processes, probabilistic automata, probabilistic timed automata, partially observable models, and interval models. Costs and rewards can extend its models. Its property language includes PCTL, CSL, LTL, and PCTL*, along with quantitative and costs-and-rewards extensions. Analysis options include symbolic algorithms based on BDDs and MTBDDs, discrete-event simulation for approximate or statistical checking, quantitative abstraction refinement, and symmetry reduction. PRISM supports the PRISM language, PEPA, and SBML, with temporal-logic formalisms and counterexamples. Version 4.10.1 supports UMB import and export and imports POMDPs from explicit files. The free, open-source software runs on Linux, Windows, and macOS and is distributed under GNU General Public License version 2. It requires Java 11 or later; binary distributions require the Java Runtime Environment.

Who it suits

PRISM suits people formally analyzing systems whose behavior involves probability, including security-related systems such as anonymity, threats, and cryptography protocols. It is relevant to users comfortable with model-checking formalisms and a Java prerequisite.

What it does well

Supports multiple probabilistic model types.
Includes symbolic, simulation, and abstraction-refinement methods.
Free and open source under GNU GPL version 2.
Runs on Linux, Windows, and macOS.

What to know first

Requires Java 11 or later.
Binary distributions require the Java Runtime Environment.

Limits

Running PRISM requires Java 11 or later. Binary distributions also require the Java Runtime Environment.

Plans

Plan	Billed and limits	Price
PRISM	Free and open source · GNU General Public License, version 2	Free

As prismmodelchecker.org lists them, read 7 Oct 2026. The maker's own page has the final word.

Getting started

Visit the PRISM website.
Choose a distribution for Linux, Windows or macOS.
Ensure Java 11 or later is available; binary distributions require the Java Runtime Environment.
Consult the manual or FAQ for guidance, or use the forum or GitHub issue tracker for questions and feedback.

Verdict

PRISM supports a broad range of probabilistic models and analysis methods, and is free to use. Check the Java requirement and supported input formats before choosing it.

Questions

Is PRISM free?

Yes. It is free and open source under GNU General Public License version 2.

Which operating systems does PRISM support?

It is known to run on Linux, Windows and macOS, in both 32-bit and 64-bit versions.

What Java version does PRISM require?

Running PRISM requires Java 11 or later. Binary distributions require the Java Runtime Environment.

Which input languages does PRISM support?

The listed input languages are the PRISM language, PEPA and SBML.

What model types can PRISM analyse?

It supports Markov chains, Markov decision processes, probabilistic automata, probabilistic timed automata, partially observable models and interval models.

Who maintains PRISM?

The project says it was created and is actively maintained by Dave Parker, Gethin Norman and Marta Kwiatkowska, with development currently led from Oxford by Dave Parker.

Facts from PRISM's own pages

Analysis methods: PRISM includes BDD and MTBDD based symbolic algorithms, discrete-event simulation for approximate or statistical model checking, quantitative abstraction refinement, and symmetry reduction. · prismmodelchecker.org, 7 Oct 2026
Distribution: PRISM is distributed under the GNU General Public License, version 2. · prismmodelchecker.org, 7 Oct 2026
Import and export: Version 4.10.1 supports import and export using UMB format, imports POMDPs from explicit files, and can optionally export or import initial state information via a .tra file. · prismmodelchecker.org, 7 Oct 2026
Latest release: The download page lists version 4.10.1, first released on 2 April 2026. · prismmodelchecker.org, 7 Oct 2026
Maintainers: The site says PRISM was created and is actively maintained by Dave Parker, Gethin Norman, and Marta Kwiatkowska, with development currently led from Oxford by Dave Parker. · prismmodelchecker.org, 7 Oct 2026
Model types: It supports discrete-time and continuous-time Markov chains, Markov decision processes, probabilistic automata, probabilistic timed automata, partially observable models, and interval models. · prismmodelchecker.org, 7 Oct 2026
Prerequisite: Running PRISM requires Java version 11 or above; binary distributions require the Java Runtime Environment. · prismmodelchecker.org, 7 Oct 2026
Purpose: PRISM is a probabilistic model checker for formal modelling and analysis of systems with random or probabilistic behaviour. · prismmodelchecker.org, 7 Oct 2026
Rewards and costs: PRISM supports extensions of its models with costs and rewards. · prismmodelchecker.org, 7 Oct 2026
Security use cases: The case studies include analysis of security-related systems, including contract signing, anonymity, threats and attacks, and quantum cryptography protocols. · prismmodelchecker.org, 7 Oct 2026
Specifications: Its property specification language incorporates PCTL, CSL, LTL, and PCTL*, as well as quantitative and costs/rewards extensions. · prismmodelchecker.org, 7 Oct 2026
Support: The project directs users to its FAQ and manual, and invites other questions, feedback, bug reports, and feature requests through its forum or GitHub issue tracker. · prismmodelchecker.org, 7 Oct 2026
Supported operating systems: The site says PRISM is known to run on Linux, Windows, and macOS, in both 32-bit and 64-bit versions. · prismmodelchecker.org, 7 Oct 2026

Where PRISM stands on Freedom251

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