Directory

Language-independent columnar in-memory format and libraries that let DuckDB, Polars, pandas, Spark and databases exchange tables without copying

Extensible Rust query engine built on Apache Arrow offering SQL and DataFrame APIs, Parquet readers and an optimizer for embedding in data systems

Distributed data processing engine with DataFrame and SQL APIs in Python, Scala, Java and R, plus structured streaming and MLlib

Kevin Sheppard's Python package for univariate ARCH/GARCH volatility models, bootstraps, multiple-comparison procedures, unit-root and cointegration tests

Microsoft's multi-agent framework (Core, AgentChat, Extensions, Studio) for Python and .NET, now archived with users directed to Microsoft Agent Framework

Redis-backed job and message queue for Node.js (with a Python port) offering workers, flows, rate limiting, repeatable jobs and a commercial Pro tier

All-in-one JavaScript and TypeScript runtime, package manager, bundler and test runner built on JavaScriptCore by Oven

Open-source embedding database with a minimal Python and JavaScript API, usable in-process, as a server or through Chroma Cloud

Open-source crawling and scraping library for Node.js/TypeScript and Python that unifies HTTP and headless-browser crawlers with queues, proxies, fingerprints and storage

Open-source Python framework for role-based multi-agent crews and event-driven flows, with a commercial enterprise console for deploying, monitoring and triggering automations

End-to-end and component testing framework that runs tests inside the browser with an interactive runner, paired with the commercial Cypress Cloud

Asset-oriented Python orchestrator that models pipelines as software-defined data assets with lineage, checks and a hosted Dagster+ option

Python library for parallel and distributed computing that scales pandas, NumPy and custom task graphs from a laptop to a cluster

Secure-by-default JavaScript and TypeScript runtime from Deno Land with web-standard APIs, built-in tooling and an optional hosted Deploy service

React-based static site generator from Meta for documentation sites with MDX content, versioning, localization and a plugin architecture

Python causal-inference library organized around model, identify, estimate and refute steps, with graphical causal models for attribution, counterfactuals and root-cause analysis

Python framework for programming language-model pipelines with typed signatures and modules, then optimizing prompts and weights automatically against a metric

In-process analytical SQL database that queries Parquet, CSV and Arrow data directly from Python, R, Node or the CLI

Python library for heterogeneous treatment-effect estimation with machine learning: double ML, doubly robust learners, causal forests, meta-learners, IV and policy learning

MIT-licensed Python library for SEC EDGAR: company and filing objects, XBRL financial statements, Form 3/4/5, 13F and proxy parsing into pandas, with the SEC identity requirement built in

Pluggable static analysis tool for JavaScript and TypeScript that finds problems in code through configurable rules and can fix many automatically

Minimal, unopinionated web framework for Node.js with routing and middleware, the long-standing default for HTTP servers in the Node ecosystem

Python web framework for building HTTP APIs from type-annotated functions, with automatic validation through Pydantic and generated OpenAPI documentation

R package for fast estimation of OLS, GLM, Poisson, IV and difference-in-differences models with many fixed effects, clustered errors, multiple estimations and publication tables