🎉 Huub v100.0.0 – First Public Release

[Dekker1]

We’re excited to announce the first public release of Huub, a CP+SAT solver written in Rust: v100.0.0.

Huub combines constraint programming with SAT solving and is designed for both practical use and experimentation.

What is Huub?

Huub can be used in two main ways:

• As a MiniZinc backend
• As a standalone Rust library for building custom solvers

A core goal of the project is to make it easy to experiment with and extend solver behaviour, whether that’s integrating new ideas, prototyping research, or building domain-specific solving approaches.

Key features

• Extensible architecture: designed to allow adding new functionality and experimenting with solver components
• IPASIR-UP based integration: enabling the use of different underlying SAT solvers
• Access to modern SAT features (e.g. via CaDiCaL)

Huub has been under development for several years and achieved 3rd place in the MiniZinc Challenge (2025).

Getting started

You can find documentation and examples here:

• 🌐 https://huub.solutions
• 📚 https://docs.rs/huub

We recommend starting with the examples to get a quick overview of usage.

A small note on the version

Huub is named after my grandfather, who would have turned 100 this year. He spent many hours constructing school timetables by hand — solving exactly the kinds of problems Huub is designed for.
From here on, Huub will follow semantic versioning.

Feedback

We’d love to hear your feedback, whether you’re:

• using Huub with MiniZinc
• experimenting with the Rust API
• or exploring new solver ideas

Please don't hesitate to start a discussion here.

Acknowledgements

Many thanks to the team, @AllenZzw and @pstuckey, and the many contributors who helped shape Huub.

This work was supported by OPTIMA and by an Amazon Research Award.