Prerequisites

OntoLogos is a Rust workspace with optional Python bindings. Pick the row that matches your task. Install channels: Install and channels.

Unfamiliar with OWL terms? See the Glossary.

Decision table

Task	Rust	Python	Clone repo?
Embed reasoning in a Rust app (crates.io)	1.88+	—	No
pip install ontologos	—	3.10+ (wheels on Linux/macOS/Windows)	No
Build ontologos-cli from source	1.88+	—	Yes
Run full conformance / benchmarks	1.88+	3.10+ optional	Yes + ./benchmarks/scripts/download.sh
MSRV CI gate	1.88 exactly	—	Yes
Contribute (fmt, clippy, tests)	stable (1.88+)	3.10+ for ontologos-py	Yes

MSRV: Rust 1.88 (workspace Cargo.toml rust-version; CI msrv job enforces exactly 1.88).

Rust toolchain

rustup update stable
rustup component add rustfmt clippy
rustc --version   # must be >= 1.88.0

If rustc is too old, see Troubleshooting — rustc version.

New projects from crates.io only need a standard Cargo workspace—no fork of this repository.

Python toolchain

pip install ontologos
python -c "from ontologos import Reasoner; print('ok')"

Optional extras: pip install 'ontologos[pandas]' or 'ontologos[polars]' for DataFrame export.

Development install from a clone: see Python guide.

CLI from git (not on crates.io)

git clone https://github.com/eddiethedean/ontologos.git
cd ontologos
cargo build -p ontologos-cli --release
./target/release/ontologos --help

Benchmark corpora (clone only)

Family ontology is vendored. Pizza and other HermiT fixtures:

./benchmarks/scripts/download.sh

What you do not need

Misconception	Reality
Protégé installed	Optional for authoring OWL; not required to run OntoLogos
Java / HermiT	OntoLogos does not embed HermiT; conformance tests compare against ported fixtures
Every crate on crates.io	ontologos-cli and ontologos-conformance are source-build only

Next step

Start here — pick a persona path.