HOL Light vs Viper
| HOL Light | Viper | |
|---|---|---|
| Free plan | No | No |
| Free trial | No | No |
| Paid from | — | — |
| Open source | No | No |
| Platforms | Linux, macOS, self-hosted, Web, Windows | Windows, macOS, Linux |
| Free plan | Yes | Yes |
| Verification method | deductive | hybrid |
| Supported formalisms | theorem-proving | contracts |
| Input languages | OCaml; higher-order logic | Viper language; Go, Python, and Rust via front-end tools |
| Deployment | self-hosted | self-hosted |
| Counterexamples | — | Yes |
Both are listed in Best Formal Verification Tools. On Inferse, HOL Light scores higher on our published basis.