Source: https://seerepo.com/compare/Aider-AI/aider/vs/harvard-edge/cs249r_book
Markdown source: https://seerepo.com/compare/Aider-AI/aider/vs/harvard-edge/cs249r_book.md
Description: aider and cs249r_book share 29 technologies: pyarrow, anyio, tornado, cycler, fonttools, soupsieve, contourpy, matplotlib, Rich, prompt-toolkit, nltk, OpenAI, scikit-learn, sentence-transformers, torch, transformers, jinja2, markdown-it-py, markupsafe, mdurl, pillow, beautifulsoup4, pypandoc, annotated-types, jsonschema-specifications, Pydantic, referencing, jsonschema, and psutil. Both are written in Python.

# aider vs cs249r_book

aider and cs249r_book share 29 technologies: pyarrow, anyio, tornado, cycler, fonttools, soupsieve, contourpy, matplotlib, Rich, prompt-toolkit, nltk, OpenAI, scikit-learn, sentence-transformers, torch, transformers, jinja2, markdown-it-py, markupsafe, mdurl, pillow, beautifulsoup4, pypandoc, annotated-types, jsonschema-specifications, Pydantic, referencing, jsonschema, and psutil. Both are written in Python.

- [Aider-AI/aider](https://seerepo.com/r/Aider-AI/aider): aider is AI pair programming in your terminal
- [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

## What they share and what sets them apart

- In common: pyarrow, anyio, tornado, cycler, fonttools, soupsieve, contourpy, matplotlib, Rich, prompt-toolkit, nltk, OpenAI, scikit-learn, sentence-transformers, torch, transformers, jinja2, markdown-it-py, markupsafe, mdurl, pillow, beautifulsoup4, pypandoc, annotated-types, jsonschema-specifications, Pydantic, referencing, jsonschema, psutil
- Only in aider: aiosqlite, gitdb, google-cloud-core, SQLite, diskcache, PostHog, AIOHTTP, asgiref, FastAPI, starlette, Streamlit, SQLAlchemy, cryptography, Google, llama-index-instrumentation, llama-index-workflows, safetensors, tiktoken, tokenizers, litellm, llama-index-core, llama-index-embeddings-huggingface, filetype, tinytag, marshmallow
- Only in cs249r_book: async-lru, pyzmq, requests-cache, jupyter-core, jupyterlab-server, Vite, React, idb, Next.js, jupyterlab-pygments, tinycss2, ipywidgets, jupyter-server-terminals, jupyterlab-widgets, matplotlib-inline, seaborn, widgetsnbextension, Plotly, argon2-cffi, argon2-cffi-bindings, groq, Ollama, torchvision, librosa, torch-geometric, bleach, defusedxml, ghostscript, mistune, nbconvert, pandocfilters, pylatexenc, python-frontmatter, tablib, webencodings, xlrd, xlwt, xmltodict, lxml, jupytext, nbformat, cattrs, fastjsonschema, fqdn, rfc3339-validator, rfc3986-validator, pydantic-core, prometheus-client, python-json-logger, Tailwind CSS, Mermaid, Chart.js, D3, compromise, katex, dompurify, markdown-it, markdown-it-container, jspdf, jspdf-autotable, Framer, react-medium-image-zoom, Lucide

## Side by side

| | aider | cs249r_book |
|---|---|---|
| Size | 40,345 lines written, 80 code files | 821,581 lines written, 1,977 code files |
| Who writes it | 89.5% of its commits signed by AI. With Aider, Gemini CLI, Codex, and Claude Code | 2.7% of its commits signed by AI. With Codex, Claude Code, Gemini CLI, and Cursor |
| Activity | Last push May 22, 2026, 12,461 commits, 49,968 stars | Last push November 8, 2026, 22,351 commits, 30,011 stars |
| Tests | 57 test files. 42.5% of its code files have a test that imports them | 629 test files. 16.6% 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, aider or cs249r_book?

cs249r_book, with 821,581 lines written; aider has 40,345.

The proof: [harvard-edge/cs249r_book's code at commit de87c01](https://github.com/harvard-edge/cs249r_book/tree/de87c0103806d7bfb1c677dbb77a2b92fa00c298)

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

aider, with 49,968 stars; cs249r_book has 30,011.

The proof: [Aider-AI/aider on GitHub](https://github.com/Aider-AI/aider)

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

cs249r_book, with 629 test files; aider has 57.

The proof: [harvard-edge/cs249r_book's code at commit de87c01](https://github.com/harvard-edge/cs249r_book/tree/de87c0103806d7bfb1c677dbb77a2b92fa00c298)

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

cs249r_book: its last push was on November 8, 2026, and aider's on May 22, 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, aider or cs249r_book?

aider: an AI signed 89.5% of its commits, with Aider, Gemini CLI, Codex, and Claude Code; in cs249r_book, 2.7%.

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

## Sources

- Aider-AI/aider: Read on November 5, 2026, at commit 5dc9490 (https://github.com/Aider-AI/aider/tree/5dc9490bb35f9729ef2c95d00a19ccd30c26339c)
- harvard-edge/cs249r_book: Read on November 8, 2026, at commit de87c01 (https://github.com/harvard-edge/cs249r_book/tree/de87c0103806d7bfb1c677dbb77a2b92fa00c298)

## 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.