Side by side
OpenJML vs Rocq
Both stand on formal verification tools. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan APIExtensionLinux+2
Choose OpenJML if you need a free, self-hosted way to check Java programs against JML specifications, with both deductive verification and runtime assertion checking. Look elsewhere if test suite generation or supported integration with Eclipse, Visual Studio, IntelliJ, or LSP is essential.
Visit OpenJML
Free plan ExtensionLinuxMac+2
Rocq provides proof checking, automation methods and certified program extraction within a language for mathematics and specification. Linux users should note that installation is script-based rather than through a Platform binary installer.
Visit RocqThe facts
| OpenJML | Rocq | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | API, Extension, Linux, Mac, Windows | Extension, Linux, Mac, Web, Windows |
| Lowest paid plan | Free or on request | Free or on request |
| Plans published | 1 | 1 |
| Maker | Not published | Not published |
| Website | openjml.org | rocq-prover.org |
| On formal verification tools | #12 of 34 | #16 of 34 |
OpenJML: what it does well
- Free, open-source command-line tool licensed under GPL version 2.
- Provides static deductive verification and runtime assertion checking.
- Supports contracts and counterexamples for Java and JML input.
- Bundles a selection of SMT solvers with releases.
- Language server offers navigation, highlighting, syntax coloring, and diagnostics.
What to know first
- Test suite generation is not yet supported.
- Listed Eclipse, Visual Studio, IntelliJ, and LSP integrations are obsolete and unsupported.
- VS Code and Eclipse extensions require an OpenJML installation.
- Runtime assertion checking generally covers Java elements through Java 7, with exceptions.
Rocq: what it does well
- Checks proofs with a certification kernel.
- Can extract programs to OCaml, Haskell or Scheme.
- Offers interactive methods and a tactic language.
- Platform bundles the prover with libraries and plugins.
- Free under the GNU Lesser General Public Licence Version 2.1.
What to know first
- No Rocq Platform binary installer for Linux.
- Precompiled installers are listed only for macOS and Windows.
- Requires work with formal proofs and specifications.