A 2014 deep-learning library the author already abandoned
Hebel was a PyCUDA-powered neural net toolkit before PyTorch existed; its creator now recommends Chainer instead.

What it does Hebel trains feed-forward neural networks for classification and regression, using CUDA acceleration via PyCUDA. It bundles the standard 2014 toolkit: dropout, L1/L2 weight decay, SGD with regular and Nesterov momentum, plus YAML-driven configuration files for running experiments.
The interesting bit The author, Hannes Bretschneider, formally disowned it in the README itself — “I no longer actively develop Hebel” — and pointed readers to Chainer. That makes Hebel a small time capsule: a pre-TensorFlow, pre-PyTorch attempt at GPU deep learning in Python, back when “GPU acceleration” still meant writing PyCUDA kernels by hand.
Key highlights
- Feed-forward nets only; CNNs, autoencoders, and RBMs were “planned for the future” and apparently never arrived
- Configuration-driven training via YAML files in
examples/ - pip-installable (
pip install hebel) with docs on ReadTheDocs - Published with a Zenodo DOI for academic citation
- Runs on Linux and Windows; macOS “probably” works but was never tested
Caveats
- The author explicitly recommends against using it
- No commits or active maintenance; dependencies like PyCUDA and skdata are increasingly dated
- “Planned” models (CNNs, RBMs) never materialized per the README
Verdict Curious historians of deep-learning tooling might clone it to see how pre-framework GPU nets felt. Anyone who actually needs to train a neural network in 2024 should follow Bretschneider’s own advice and look elsewhere.
Frequently asked
- What is hannes-brt/hebel?
- Hebel was a PyCUDA-powered neural net toolkit before PyTorch existed; its creator now recommends Chainer instead.
- Is hebel open source?
- Yes — hannes-brt/hebel is open source, released under the GPL-2.0 license.
- What language is hebel written in?
- hannes-brt/hebel is primarily written in Python.
- How popular is hebel?
- hannes-brt/hebel has 1.2k stars on GitHub.
- Where can I find hebel?
- hannes-brt/hebel is on GitHub at https://github.com/hannes-brt/hebel.