Open Source Repos

Platform to programmatically author, schedule and monitor workflows.

In-memory columnar format for analytics and high-speed data interchange.

Powerful, interactive charting and visualization library for the web.

Unified analytics engine for large-scale data processing.

Modern, enterprise-ready business intelligence web application.

Low-code platform to build internal tools and admin dashboards fast.

Open-source backend server - auth, database, storage and functions in one.

Modern load and smoke testing toolkit for APIs, WebSockets and game backends.

Framework for building multi-agent AI applications and workflows.

Swiss-army knife for network attacks, monitoring, sniffing and MITM.

Make AI agents control a real browser to browse, click and gather data autonomously.

Make polished launch and product demo videos.

Simple yet flexible JavaScript charting for designers and developers.

Official plugins for contract review and legal workflows.

Open-source columnar database for real-time analytics at massive scale.

Local-first tracker for AI coding spend - token usage and cost across 40+ tools (Claude, Cursor, Codex…), by model, project and task.

Lightning-fast and elegant scraping framework for Go.

Node-based interface for stable diffusion image-generation workflows.

Sign, verify and attest container images and artifacts for supply-chain provenance (Sigstore).

Enterprise-grade product analytics for web, mobile and IoT.

Fast, open-source LLM-friendly web crawler that turns any page into clean markdown for RAG and agents.

Web scraping and browser automation library for Node.js - the successor to the Apify SDK.

Framework for orchestrating role-playing, autonomous AI agents.

Open-source, Descript-style text-based video editor - delete words from a transcript to cut audio/video, with AI filler removal and captions.

Fast, easy and reliable testing for anything that runs in a browser.

Data-driven documents - bring data to life with SVG, Canvas and HTML.

Open metadata platform for the modern data stack - search, catalog and column-level lineage.

Data plus LLM agent platform - text-to-SQL, RAG and private deployment.

Analytics engineering tool - transform data in your warehouse with SQL.

LLM evaluation framework - unit-test LLM outputs like you test code.

Open-source platform for building and running AI agents and workflows.

Open data platform - instant REST and GraphQL API over any SQL database.

The open container engine - package apps into portable, runnable images.

Headless TypeScript ORM with SQL-like syntax and zero magic.

In-process analytical database - run fast SQL directly on CSV, Parquet and JSON files with zero infrastructure.

Distributed search and analytics engine built on Apache Lucene.

Virtual whiteboard for sketching diagrams with a hand-drawn feel.

Framework and platform for universal React apps - iOS, Android and web.

Property-based testing for JavaScript and TypeScript - generate inputs to find edge cases.

Open platform for training, serving and evaluating LLM chatbots.

Complete cross-platform solution to record, convert and stream audio and video.

Crawl and scrape websites into clean, LLM-ready markdown or structured data - hosted API or self-host.

Drag-and-drop UI to build LLM apps and agents with LangChain under the hood.

Fluent, readable assertion library for .NET unit tests.

Run surveys inside your product to understand onboarding, churn, and feedback.

Production-ready animation library for React - gestures, layout and shared transitions.

High-performance load and stress testing for HTTP systems with a Scala DSL.

Scan git repos and files for secrets, keys and passwords before they leak.

Crawl a website to generate knowledge files you can feed to an LLM.

Build and share delightful machine learning web demos in Python.

Open observability platform - dashboards, metrics, logs and alerts in one place.

Developer-first load testing tool for APIs and websites, scriptable in JavaScript.

Horizontally scalable, cost-effective log aggregation inspired by Prometheus.

Open-source alternative to Tableau - an embeddable, no-code visual analytics interface for exploring data with drag-and-drop charts.

Turn any codebase - code, docs, SQL, PDFs - into a queryable knowledge graph your AI assistant can traverse instead of grepping files.

Vulnerability scanner for container images and filesystems with SBOM output.

Makes Claude act like a full dev team - planning, reviewing, and QA-ing your code.

Aggregate and query software supply-chain metadata - SBOMs, attestations and vulnerabilities together.

Add guardrails to LLM apps - validate and enforce schemas on model input and output.

Instant real-time GraphQL APIs over your Postgres database.

Context-compression layer for AI agents - compress tool outputs, logs, RAG chunks and history before they reach the LLM.

Beautifully crafted, accessible React UI components (formerly NextUI) with theming, Tailwind support and great DX.

HTTP load generator - fire thousands of requests from the command line.

Property-based testing for Python - find edge cases with generated inputs.

Framework to secure the software supply chain with attestations and verifiable evidence.

Open-source mobile UI toolkit for building cross-platform apps with web tech.

CNCF distributed tracing platform for monitoring and troubleshooting microservices.

NumPy with automatic differentiation and XLA acceleration on accelerators.

Delightful JavaScript testing framework with zero config and snapshot testing.

Self-hostable reader that turns any URL into clean, LLM-friendly markdown.

Distributed event streaming platform for high-throughput data pipelines.

Deep learning API for humans - runs on JAX, TensorFlow and PyTorch.

Flexible SQL query builder for Postgres, MySQL, SQLite and more.

Production-grade container orchestration - deploy, scale and manage containers.

Open-source billing for complex pricing - subscriptions, usage, seats, credits, invoices.

Framework for building LLM-powered apps with chains, agents and tools.

Open-source LLM engineering platform - tracing, evals, prompts and analytics.

Researches any topic across Reddit, X, and other social media before you build.

LLM gateway and proxy - one unified format across 100+ providers (OpenAI, Anthropic, Bedrock…) with budgets, retries and fallbacks.

Inference of LLMs in pure C/C++ - runs Llama models on CPU and GPU.

Data framework to connect LLMs with your own data via RAG indexes.

Prompt compression from Microsoft - shrink prompts up to 20x while keeping performance for cheaper, faster LLM calls.

Scalable load testing in Python - define user behaviour in plain code.

CRO, copywriting, SEO, analytics, and growth engineering for AI agents.

Convert files - PDF, Word, images, audio - to Markdown for LLM use.

Open-source metadata service that collects and visualizes lineage for data pipelines.

The Google Analytics alternative you own - full web analytics with no data limits.

Easy open-source business intelligence - ask questions and build dashboards on your data.

The world's most widely used penetration testing framework with thousands of exploits.

Purpose-built vector database for similarity search and AI applications.

Simple, flexible JavaScript test framework that runs in Node and the browser.

The most popular mocking library for .NET - set up and verify mocks easily.

Mock APIs by intercepting network requests at the service-worker level for testing.

Fair-code workflow automation with hundreds of integrations and AI nodes.

Real-time, high-resolution system and application monitoring with an agent.

Network discovery and security scanning utility used by pentesters everywhere.

Open-source Airtable alternative - turn any database into a smart spreadsheet.

One system to send and manage all your app's user notifications across email, SMS, and push.

Fast vulnerability scanner powered by a huge library of YAML templates.

The fundamental package for scientific computing in Python.

Unit-testing framework for all .NET languages - fixtures, assertions and parallelism.

Free, open-source software for video recording and live streaming.

Run Llama, Mistral and other LLMs locally with a simple CLI and API.

Massively multilingual zero-shot text-to-speech - 600+ languages with voice cloning, voice design and fine-grained control.

Self-hostable ChatGPT-style interface for local LLMs with RAG support.

Framework for evaluating LLMs and LLM-based systems from OpenAI.

AI research-draft generator - 19 agents draft long-form papers from a prompt with citations verified against CrossRef, OpenAlex and Semantic Scholar.

Open standard for collecting and sharing data lineage across your stack - Airflow, dbt, Spark and more.

All-in-one metadata platform with data discovery, lineage, data quality and governance.

Self-hosted session replay to see how users use your product and where they drop off.

Vendor-neutral standard for traces, metrics and logs - collect and export telemetry from any stack.

Privacy-first voice dictation and meeting transcription - local Whisper/Parakeet or your own cloud keys, with notes and speaker diarization.

Open-source LLM evaluation and observability platform with tracing.

Scan dependencies for known vulnerabilities using the open OSV database.

Structured generation for LLMs - make models return valid JSON, regex or grammar-conforming output every single time.

Software composition analysis that detects disclosed vulnerabilities in dependencies.

Fast, flexible data analysis and manipulation toolkit for Python.

See exactly who opened your deck, which pages they read, and what they skipped.

Lightweight, privacy-friendly open-source web analytics - no cookies, GDPR-friendly.

Reliable cross-browser end-to-end testing for the modern web.

High-level, declarative charting library for JavaScript built on D3 and WebGL.

Single-file open-source backend with realtime database, auth and file storage.

Lightning-fast DataFrame library written in Rust with a Python API.

Agent skill that makes your AI coding assistant think like the laziest senior dev - reuse, don't over-build, write only what the task needs.

All-in-one product analytics - events, funnels, session replay, feature flags and experiments.

Next-generation ORM - a type-safe database client with migrations.

Open-source monitoring and alerting toolkit for time-series metrics.

Test and red-team LLM apps - run evals for quality and safety in CI.

Data validation and settings management using Python type hints.

Mature, full-featured Python testing tool with a rich plugin ecosystem.

Open-source machine learning framework with GPU-accelerated tensors.

Vector search engine with extended filtering for AI applications.

AI agents that run your back office - built and used by YC.

Performant, flexible forms for React with easy-to-add validation.

React renderer for Three.js - build declarative 3D scenes on the web.

Standalone version of Firefox reader mode - extract the main readable content from any page.

Redefined chart library built with React and D3.

Connect to any data source, query it and build beautiful dashboards.

In-memory data structure store used as cache, message broker and database.

Predictable state container for JavaScript apps with powerful devtools.

Make videos programmatically with React - motion graphics and data-driven videos rendered to real MP4s.

Simple and efficient tools for predictive data analysis in Python.

AI-powered web scraping library that uses LLMs and graph pipelines to extract data from prompts.

Fast, high-level Python framework for web crawling and scraping at scale.

Fast, open-source static analysis that catches bugs and security issues in code.

Self-hostable error tracking and performance monitoring for your applications.

Beautifully-designed UI components you copy into your app and own.

Open-source APM and observability platform - traces, metrics and logs with an OpenTelemetry-native pipeline.

Standalone test spies, stubs and mocks for JavaScript - works with any framework.

Generate SLSA provenance for your builds straight from GitHub Actions.

Reactive UI library with fine-grained updates and compiled, zero-overhead templates.

Multithreaded asynchronous web spider and crawler written in Rust.

Automatic SQL injection and database takeover tool for penetration testing.

Browser interface for Stable Diffusion - txt2img, img2img and extensions.

Frontend workshop for building UI components and pages in isolation.

Turn Python scripts into interactive data apps in minutes.

Ready-made backend for your app - database, user logins, and file storage.

Generate SBOMs - software bills of materials - from container images and filesystems.

Utility-first CSS framework for building custom designs without leaving your HTML.

Powerful async state management - server-state hooks for React, Vue and Svelte.

Build tiny, fast, secure desktop apps with a web frontend and a Rust core.

End-to-end open-source platform for machine learning.

OpenAI's fast BPE tokenizer - count and encode tokens for GPT models and many more, in Python, Rust and JS.

Python tool for web scraping and text extraction tuned for NLP and corpus building.

State-of-the-art ML - thousands of pretrained models for NLP, vision and audio.

Comprehensive, fast vulnerability scanner for containers and IaC.

End-to-end typesafe APIs built entirely on TypeScript inference.

ORM for TypeScript and JavaScript that supports many databases.

Simple, fast, privacy-focused website analytics with a clean dashboard.

Self-hosted uptime monitoring with status pages, heartbeats and rich notifications.

HTTP load testing tool and library with constant request-rate attack mode.

Blazing-fast unit test framework for Vite projects with first-class ESM and TypeScript.

High-throughput LLM serving engine - PagedAttention, continuous batching and an OpenAI-compatible server for thousands of models.

Open-source vector database with semantic and hybrid search.

Robust speech recognition via large-scale weak supervision.

The world's most popular network protocol analyzer for packet inspection.

.NET unit testing framework by the creators of NUnit v2 - runs on .NET Core.

OWASP Zed Attack Proxy - find vulnerabilities in web applications as you develop.

Small, fast state-management store for React built on hooks.