Source: https://seerepo.com/compare/harvard-edge/cs249r_book/vs/ray-project/ray
Markdown source: https://seerepo.com/compare/harvard-edge/cs249r_book/vs/ray-project/ray.md
Description: cs249r_book and ray share 59 technologies: async-lru, pyzmq, pyarrow, anyio, jupyter-core, jupyterlab-server, tornado, React, cycler, fonttools, jupyterlab-pygments, soupsieve, tinycss2, contourpy, ipywidgets, jupyter-server-terminals, jupyterlab-widgets, matplotlib-inline, prompt-toolkit, widgetsnbextension, Rich, matplotlib, Plotly, argon2-cffi, argon2-cffi-bindings, torch, transformers, torchvision, scikit-learn, nltk, bleach, defusedxml, jinja2, markdown-it-py, markupsafe, mdurl, mistune, nbconvert, pandocfilters, webencodings, xlrd, xmltodict, beautifulsoup4, pillow, lxml, nbformat, annotated-types, fastjsonschema, fqdn, jsonschema-specifications, referencing, rfc3339-validator, rfc3986-validator, Pydantic, jsonschema, pydantic-core, prometheus-client, python-json-logger, and psutil. Both are written in Python.

# cs249r_book vs ray

cs249r_book and ray share 59 technologies: async-lru, pyzmq, pyarrow, anyio, jupyter-core, jupyterlab-server, tornado, React, cycler, fonttools, jupyterlab-pygments, soupsieve, tinycss2, contourpy, ipywidgets, jupyter-server-terminals, jupyterlab-widgets, matplotlib-inline, prompt-toolkit, widgetsnbextension, Rich, matplotlib, Plotly, argon2-cffi, argon2-cffi-bindings, torch, transformers, torchvision, scikit-learn, nltk, bleach, defusedxml, jinja2, markdown-it-py, markupsafe, mdurl, mistune, nbconvert, pandocfilters, webencodings, xlrd, xmltodict, beautifulsoup4, pillow, lxml, nbformat, annotated-types, fastjsonschema, fqdn, jsonschema-specifications, referencing, rfc3339-validator, rfc3986-validator, Pydantic, jsonschema, pydantic-core, prometheus-client, python-json-logger, and psutil. Both are written in Python.

- [harvard-edge/cs249r_book](https://seerepo.com/r/harvard-edge/cs249r_book): Machine Learning Systems: Foundations, Scaling, Agentic AI, and Physical AI (Vols I–IV) • Harvard CS249r | https://mlsysbook.ai
- [ray-project/ray](https://seerepo.com/r/ray-project/ray): Ray is an AI compute engine. Ray consists of a core distributed runtime and a set of AI Libraries for accelerating ML workloads.

## What they share and what sets them apart

- In common: async-lru, pyzmq, pyarrow, anyio, jupyter-core, jupyterlab-server, tornado, React, cycler, fonttools, jupyterlab-pygments, soupsieve, tinycss2, contourpy, ipywidgets, jupyter-server-terminals, jupyterlab-widgets, matplotlib-inline, prompt-toolkit, widgetsnbextension, Rich, matplotlib, Plotly, argon2-cffi, argon2-cffi-bindings, torch, transformers, torchvision, scikit-learn, nltk, bleach, defusedxml, jinja2, markdown-it-py, markupsafe, mdurl, mistune, nbconvert, pandocfilters, webencodings, xlrd, xmltodict, beautifulsoup4, pillow, lxml, nbformat, annotated-types, fastjsonschema, fqdn, jsonschema-specifications, referencing, rfc3339-validator, rfc3986-validator, Pydantic, jsonschema, pydantic-core, prometheus-client, python-json-logger, psutil
- Only in cs249r_book: requests-cache, Vite, idb, Next.js, seaborn, groq, Ollama, OpenAI, sentence-transformers, librosa, torch-geometric, ghostscript, pylatexenc, pypandoc, python-frontmatter, tablib, xlwt, jupytext, cattrs, Tailwind CSS, Mermaid, Chart.js, D3, compromise, katex, dompurify, markdown-it, markdown-it-container, jspdf, jspdf-autotable, Framer, react-medium-image-zoom, Lucide
- Only in ray: FastAPI, amqp, azure-common, azure-datalake-store, azure-storage-blob, confluent-kafka, diskcache, expiringdict, gitdb, google-cloud-core, h5py, kombu, pickleshare, pylance, pymongo, aioboto3, MongoDB, Redis, adlfs, smart-open, pyiceberg, pymysql, clickhouse-connect, deltalake, gcsfs, Celery, fastavro, s3fs, webdataset, Google, Hugging Face, Google Cloud Storage, Kafka, asgiref, Flask, flask-cors, graphene, graphql-core, graphql-relay, werkzeug, Ray, starlette, AIOHTTP, Lightning, uvicorn, react-router-dom, alabaster, pydata-sphinx-theme, sphinx-design, glfw, pyopengl, Textual, xyzservices, Gradio, pydot, alembic, peewee, sqlglot, SQLAlchemy, azure-identity, flask-basicauth, google-auth-oauthlib, itsdangerous, joserfc, jwcrypto, keyring, msal, msal-extensions, oauth2client, oauthlib, pyjwt, requests-oauthlib, cryptography, google-auth-httplib2, albucore, bitsandbytes, cmdstanpy, crcmod, cupy-cuda12x, cupy-cuda13x, einops, fairscale, gradio-client, gym, LangChain, llvmlite, lm-eval, ml-dtypes, MLflow, ONNX, onnxruntime, onnxscript, openai-whisper, opt-einsum, orbax-checkpoint, peft, prophet, rouge-score, sacrebleu, safetensors, scikit-image, sentencepiece, skops, tf-keras, tiktoken, timm, tokenizers, torchtext, triton, gymnasium, TensorFlow, jax, xgboost, lightgbm, accelerate, datasets, pytorch-lightning, evaluate, flax, Keras, torchmetrics, albumentations, deepspeed, diffusers, hyperopt, Optuna, pettingzoo, tensordict, tensorflow-datasets, tensorflow-probability, torchaudio, et-xmlfile, imageio, imageio-ffmpeg, imagesize, jsonlines, linkify-it-py, mako, markdown, moviepy, nh3, openpyxl, ruamel-yaml, docutils, av, torchcodec, pathvalidate, rfc3986, validators, openapi-schema-validator, aiobotocore, azure-mgmt-compute, azure-mgmt-resource, colorlog, Gunicorn, opentelemetry-api, opentelemetry-instrumentation, opentelemetry-semantic-conventions, boto3, botocore, OpenTelemetry, kubernetes, opentelemetry-exporter-prometheus, docker, opentelemetry-exporter-otlp-proto-grpc, opentelemetry-instrumentation-fastapi, typeface-roboto, MUI, usehooks-ts, lowlight, react-window, react-icons, @mui/icons-material, js-yaml

## Side by side

| | cs249r_book | ray |
|---|---|---|
| Size | 821,581 lines written, 1,977 code files | 1,531,664 lines written, 2,777 code files |
| Who writes it | 2.7% of its commits signed by AI. With Codex, Claude Code, Gemini CLI, and Cursor | 3.6% of its commits signed by AI. With Claude Code, Gemini CLI, GitHub Copilot, Cursor, and Codex |
| Activity | Last push November 8, 2026, 22,351 commits, 30,011 stars | Last push November 6, 2026, 32,373 commits, 44,213 stars |
| Tests | 629 test files. 16.6% of its code files have a test that imports them | 2,168 test files. 9.7% of its code files have a test that imports them |

- Size: Lines written by people and agents, without generated ones; code files, without tests.
- Who writes it: A commit counts as AI's when it carries its signature: a Co-Authored-By line, its author name or the merge of its branch.
- Activity: From GitHub and its history, on the day SeeRepo read it.
- Tests: The files that test the code, and the share of code files a test imports.

## Frequently asked questions

### Which is bigger, cs249r_book or ray?

ray, with 1,531,664 lines written; cs249r_book has 821,581.

The proof: [ray-project/ray's code at commit 77567c5](https://github.com/ray-project/ray/tree/77567c5c5790e9e91aa40a5af93004ef958c2ffc)

### Which has more GitHub stars, cs249r_book or ray?

ray, with 44,213 stars; cs249r_book has 30,011.

The proof: [ray-project/ray on GitHub](https://github.com/ray-project/ray)

### Which has more tests, cs249r_book or ray?

ray, with 2,168 test files; cs249r_book has 629.

The proof: [ray-project/ray's code at commit 77567c5](https://github.com/ray-project/ray/tree/77567c5c5790e9e91aa40a5af93004ef958c2ffc)

### Which was updated more recently, cs249r_book or ray?

cs249r_book: its last push was on November 8, 2026, and ray's on November 6, 2026.

The proof: [harvard-edge/cs249r_book's commits on GitHub](https://github.com/harvard-edge/cs249r_book/commits)

### Which has more commits signed by AI, cs249r_book or ray?

ray: an AI signed 3.6% of its commits, with Claude Code, Gemini CLI, GitHub Copilot, Cursor, and Codex; in cs249r_book, 2.7%.

The proof: [the commits each tool signed in ray-project/ray](https://seerepo.com/r/ray-project/ray/ai)

## Sources

- harvard-edge/cs249r_book: Read on November 8, 2026, at commit de87c01 (https://github.com/harvard-edge/cs249r_book/tree/de87c0103806d7bfb1c677dbb77a2b92fa00c298)
- ray-project/ray: Read on November 6, 2026, at commit 77567c5 (https://github.com/ray-project/ray/tree/77567c5c5790e9e91aa40a5af93004ef958c2ffc)

## What is your repo built with?

Any public repo, with no account: https://seerepo.com/r/owner/repo/built, with the owner and name it has on GitHub.