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Ultimate Automizer

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What Ultimate Automizer is

Ultimate Automizer is a software model checker in the Ultimate program analysis framework. The framework’s toolchains can check whether a C program satisfies a given specification, and Automizer can be used to verify C programs through a web interface. The project also provides regular releases for Windows and Linux, with command-line versions of Automizer available in its archives.

Automizer’s method is based on automata and uses the Ultimate Automata Library. It applies trace abstraction: proofs that individual program traces cannot occur are generalized into Floyd-Hoare automata that cover broader parts of a program. For concurrent programs, it uses an automata model based on Petri nets. The documented command-line interface takes an SV-COMP property file along with either a C file or a C file paired with a matching GraphML witness. The listed input languages are C and Boogie, and deployment is available both through the web and on-premise. Ultimate is free. Its core and many plugins are licensed under LGPLv3 with a linking exception to Eclipse RCP and Eclipse CDT. The project describes most developers as students and researchers in the University of Freiburg software engineering group; the Automizer page identifies Matthias Heizmann as maintainer.

Who it suits

Ultimate Automizer is suited to people who need to check whether C programs meet specifications, including researchers and developers working with program verification. Its web interface offers a way to verify C programs, while its Windows and Linux releases include command-line versions.

What it does well

Free to use, with web and on-premise deployment.
Web interface supports verification of C programs.
Command-line archives are available for Windows and Linux.
Trace abstraction generalizes infeasibility proofs across program traces.
Uses a Petri-net-based automata model for concurrency.

What to know first

The documented command-line input requires an SV-COMP property file.
Command-line use requires a C file, optionally with a matching GraphML witness.
The stated LGPLv3 terms apply to the core and many plugins, with a linking exception.

Getting started

Visit the Ultimate project website.
Choose the web interface or obtain a regular Windows or Linux release.
For command-line use, provide an SV-COMP property file.
Provide a C file, with a matching GraphML witness if applicable.

Verdict

Pick Ultimate Automizer if you need a free model checker for verifying C programs and want a web interface or Windows and Linux command-line releases. Its documented command-line workflow is centered on an SV-COMP property file and C input, so check that format against your verification workflow.

Questions

Is Ultimate Automizer free?

Yes. The project describes Ultimate as free, and lists a free plan with no free trial.

Which platforms are available?

The listed platforms are Linux, web, and Windows. Regular releases are provided for Windows and Linux.

What does the command-line interface accept?

It accepts an SV-COMP property file and either one C file or a C file with a matching GraphML witness.

Which input languages are listed?

C and Boogie are listed as input languages.

What license does Ultimate use?

The core of Ultimate and many plugins are licensed under LGPLv3 with a linking exception to Eclipse RCP and Eclipse CDT.

Who maintains Ultimate Automizer?

Matthias Heizmann is identified as its maintainer.

Facts from Ultimate Automizer's own pages

Audience: The project describes its developers as mostly students and researchers in the University of Freiburg software engineering group. · ultimate-pa.org, 7 Oct 2026
Award: The site reports that Ultimate Automizer won the overall ranking at SV-COMP 2026. · ultimate-pa.org, 7 Oct 2026
Command line: The available Automizer archives contain command-line versions that participated in the Competition on Software Verification. · ultimate-pa.org, 7 Oct 2026
Concurrency: For concurrency, Automizer uses a Petri-net-based automata model. · github.com, 7 Oct 2026
Development: The site says most Ultimate developers are students and researchers in Andreas Podelski’s software engineering group at the University of Freiburg. · ultimate-pa.org, 7 Oct 2026
Download: The project says it provides regular releases for Windows and Linux. · ultimate-pa.org, 7 Oct 2026
Framework: Ultimate is a program analysis framework whose toolchains can verify whether a C program fulfills a given specification. · ultimate-pa.org, 7 Oct 2026
Input: The documented command-line interface accepts an SV-COMP property file and either one C file or a C file with a matching GraphML witness. · ultimate-pa.org, 7 Oct 2026
Integration: Automizer is one toolchain within the Ultimate software analysis framework. · ultimate-pa.org, 7 Oct 2026
License: The core of Ultimate and many plugins are licensed under LGPLv3 with a linking exception to Eclipse RCP and Eclipse CDT. · ultimate-pa.org, 7 Oct 2026
Maintainer: Ultimate Automizer is maintained by Matthias Heizmann. · ultimate-pa.org, 7 Oct 2026
Method: Automizer implements an approach based on automata and uses the Ultimate Automata Library. · ultimate-pa.org, 7 Oct 2026
Product: Ultimate Automizer is a software model checker and one toolchain in the Ultimate software analysis framework. · ultimate-pa.org, 7 Oct 2026
Purpose: Ultimate Automizer is a software model checker that implements an approach based on automata. · ultimate-pa.org, 7 Oct 2026
Recognition: The Automizer page lists overall SV-COMP wins in 2016, 2017, and 2023 through 2026. · ultimate-pa.org, 7 Oct 2026
Security: The official pages opened describe program verification and provide no security or compliance certification claims. · ultimate-pa.org, 7 Oct 2026
Support: The Automizer page invites University of Freiburg students interested in contributing to contact Matthias Heizmann or another Ultimate developer. · ultimate-pa.org, 7 Oct 2026
Trace abstraction: Automizer uses trace abstraction to generalize infeasibility proofs for individual program traces to Floyd-Hoare automata covering larger parts of a program. · github.com, 7 Oct 2026
Verification: The web interface lets users verify C programs. · ultimate-pa.org, 7 Oct 2026

Where Ultimate Automizer stands on Freedom251

C and C++ Static Analysis Tools#13 of 25
Formal Verification Tools#29 of 34