Side by side
Apalache vs HOL4
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 APILinuxSelf-hosted
Apalache provides several symbolic checking modes and flexible deployment choices for TLA+ and Quint work. Review its memory needs and bounded-checking limits before relying on a particular analysis.
Visit Apalache Free plan LinuxMacSelf-hosted+1
Choose HOL4 for higher-order logic theorem proving when you need a self-hosted environment with proof tools, counterexamples, and routes to external engines. It is a weaker fit if you need a quick start: a Standard ML compiler is required, and becoming comfortable can take about a month for someone starting from scratch.
Visit HOL4The facts
| Apalache | HOL4 | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Not published |
| Runs on | API, Linux, Self-hosted | Linux, Mac, Self-hosted, Windows |
| Lowest paid plan | Not published | Free or on request |
| Plans published | None | 1 |
| Maker | Not published | Not published |
| Website | apalache-mc.org | hol-theorem-prover.org |
| On formal verification tools | #13 of 34 | #9 of 34 |
Apalache: what it does well
- Free and open-source Apache-2.0 software
- Supports TLA+ and Quint inputs
- Multiple symbolic analysis methods
- Runs via JVM package, Docker, or source
- Counterexamples supported
What to know first
- At least 4 GB memory recommended
- Bounded checks can miss longer-execution bugs
- CVC5 support is experimental
- Opt-in statistics are sent per run
HOL4: what it does well
- Free software under the Modified (3-clause) BSD licence.
- Built-in procedures and theorem provers can establish many simple theorems.
- Oracle mechanism connects to external SMT and BDD engines.
- Supports proof artifacts and counterexamples.
- Online documentation includes a tutorial, manuals, and a FAQ.
What to know first
- Requires a Standard ML compiler, with Poly/ML recommended.
- The installation page estimates about a month to become comfortable from scratch.
- Moscow ML on Windows lacks some Poly/ML libraries and concurrent Holmake builds.
Alternatives to Apalache Alternatives to HOL4 The whole list