# Open Source

Responsive web development tool

Open-source browser for responsive web development that shows multiple device viewports simultaneously with synchronized scrolling, clicking, and navigation. Preview your site on phone, tablet, and desktop sizes side by side in real-time. Features screenshot capture for all viewports, element inspector, network monitoring, and hot-reload support. Built on Chromium. Free alternative to Polypane for developers who need quick responsive testing without paid subscriptions. 23K+ GitHub stars.

Durable execution engine for workflows and AI agents

Restate is a durable execution engine that provides reliable workflow orchestration for AI agents and backend services. It runs as a single binary with no external dependencies, delivering sub-50ms latency and 94K+ actions per second. Supports TypeScript, Python, Go, Java, and Kotlin SDKs with built-in retries, sagas, and virtual object state. MIT licensed with 3,700+ GitHub stars.

Automated PR workflow with AI review and labeling

ReviewPad automates the pull request workflow by applying team-defined rules for labeling, assigning reviewers, and providing AI-powered feedback on code changes. Its open-source GitHub repository supports custom automation scripts that standardize the review cycle, making it essential for mid-to-large teams enforcing governance without sacrificing development velocity across multiple repositories.

Build modular, scalable LLM applications in Rust

Open-source Rust library for building scalable, modular, and ergonomic LLM-powered applications. Rig unifies 20+ model providers (OpenAI, Anthropic, Mistral, DeepSeek, Ollama, and more) and 10+ vector stores behind one trait-based interface, supports completion and embedding workflows, multi-turn streaming, and transcription/audio/image generation, with full GenAI Semantic Convention compatibility and WASM-ready core library — production agentic infra for Rust teams.

Visual AI agent builder by Ironclad

Rivet is an open-source visual AI programming environment and TypeScript library by Ironclad for building, debugging, and deploying AI agents through a node-based graph editor. Complex LLM prompt chains become visual networks with real-time data flow inspection at every node, team collaboration on agent graphs, and a TypeScript library for embedding finished graphs in any application. Transforms agent development from text-editing into visual engineering.

Rust-powered JavaScript bundler for Vite

Rolldown is a high-performance JavaScript and TypeScript bundler written in Rust, built as the next-generation bundler for Vite. Created by Evan You and VoidZero, it offers a Rollup-compatible plugin API with 10-30x faster builds. It combines esbuild-level speed with full Rollup ecosystem compatibility, supporting tree-shaking, code splitting, and advanced optimizations natively. With 13K+ stars and MIT license, it is set to become the default bundler for Vite 8.

Intelligent model router that balances cost and quality across LLM providers

RouteLLM by LMSYS routes LLM requests to the most cost-effective model that can handle each query's complexity. It uses learned routing models to classify whether a query needs a powerful expensive model or can be handled by a cheaper alternative, reducing costs by up to 85% while maintaining quality. Supports OpenAI, Anthropic, and other providers through an OpenAI-compatible API.

Open-source AI coworker with persistent memory and tool use

Rowboat is an open-source AI coworker platform that provides persistent memory, tool use, and multi-agent orchestration in a chat-based interface. It enables teams to build AI assistants that remember context across sessions, access internal tools and databases, and coordinate specialized sub-agents for complex workflows. Over 9,300 GitHub stars.

Extremely fast Python linter and formatter written in Rust

Ruff is a Python linter and code formatter written in Rust by Astral that runs 10-100x faster than existing tools like flake8, isort, and Black. It implements over 800 lint rules from dozens of popular plugins in a single binary, handles auto-fixing for most violations, and includes a built-in formatter compatible with Black. Adopted by FastAPI, Hugging Face, Pandas, and Apache Airflow, Ruff has over 38,000 GitHub stars and processes entire codebases in milliseconds.

Cross-platform on-device AI inference SDK

RunAnywhere SDK is a production-ready toolkit for running AI models entirely on-device across iOS, macOS, Android, Web, React Native, and Flutter. It provides a unified C++ core with platform-specific bindings for LLM text generation via llama.cpp, vision-language models, Whisper speech-to-text, Piper text-to-speech, and on-device image generation. All processing stays local with zero cloud dependency, ensuring privacy and low latency for mobile and edge AI applications.

Fast serving framework for LLMs and vision models

SGLang is an open-source serving framework for large language and vision-language models, designed for low latency and high throughput. It features RadixAttention for automatic KV cache reuse, compressed finite state machines for fast structured output generation, continuous batching, and tensor parallelism. With over 25,000 GitHub stars, it supports models like LLaMA, Mistral, Qwen, and Gemma on NVIDIA and AMD GPUs.

Build full-stack apps on your own infra

Open-source framework for building and deploying full-stack applications on AWS with infrastructure-as-code. Supports Next.js, Remix, Astro, and more with zero-config deployments. Manages Lambda, DynamoDB, S3, and other AWS services through a clean TypeScript API, giving developers the power of AWS without the complexity of CloudFormation or CDK.

Super-fast Rust-based JavaScript compiler

SWC is a super-fast JavaScript and TypeScript compiler written in Rust that serves as a drop-in replacement for Babel. It compiles modern JavaScript and TypeScript to backward-compatible versions up to 20x faster than Babel by leveraging Rust performance and parallelism. SWC handles JSX transformation, TypeScript stripping, module transpilation, and minification in a single tool, and powers major frameworks including Next.js, Parcel, and Deno.

Benchmark for evaluating AI coding agents on real GitHub issues

SWE-bench is a benchmark from Princeton NLP that evaluates AI coding agents by testing their ability to resolve real GitHub issues from popular open-source projects. Each task provides an issue description and repository state, and the agent must produce a working patch that passes the project's test suite. With 4,600+ GitHub stars, it has become the standard yardstick for comparing autonomous coding tools like Devin, Claude Code, and OpenHands.

Component toolkit for live code playgrounds

Sandpack is a component toolkit by CodeSandbox for building live-running code editing experiences directly in the browser. It bundles a full in-browser JavaScript bundler, CodeMirror editor, and preview pane into embeddable React components with npm dependency support, hot module reloading, and error overlays. Sandpack powers the interactive examples on the official React documentation and supports templates for React, Vue, Svelte, and vanilla JavaScript.

Validated agent skills and database connectors for AI co-scientist workflows

Scientific Agent Skills is an open-source library of 165+ validated agent skills and 100+ scientific database connectors. It equips AI agents across Claude Code, Cursor, and Codex with specialized workflows for biology, chemistry, and research.

LLM-powered web scraping with graph-based extraction pipelines

ScrapeGraphAI is a Python library that uses LLMs and graph-based logic to build automated, self-healing web scraping pipelines. Developers describe desired data in natural language and ScrapeGraphAI constructs a processing graph that extracts structured information from any website. It supports multiple LLM providers, achieves 96%+ accuracy on semantic extraction benchmarks, and adapts to layout changes automatically. Over 20,000 GitHub stars.

AI-native state store with hybrid vector and full-text search

SeekDB is an open-source AI-native state store from the OceanBase ecosystem that combines MySQL-compatible data access with hybrid vector and full-text retrieval. It targets agent and AI application teams that need embedded or server deployment, copy-on-write style sandboxes, and searchable state without gluing together several separate storage layers.

Microsoft's AI orchestration SDK for .NET, Python, and Java

Microsoft's open-source AI SDK that lets you combine AI models with conventional programming. Supports plugins, planners, memory, and function calling with availability for .NET, Python, and Java. Designed for enterprise developers building AI-powered applications within the Microsoft ecosystem, offering deep integration with Azure AI services and existing business logic.

Self-hosted UI and API for Ansible, Terraform, and scripts

Semaphore UI provides a web interface and REST API for running Ansible playbooks, Terraform and OpenTofu configurations, Bash scripts, and PowerShell commands from a centralized self-hosted platform. With over 13,000 GitHub stars and 2 million Docker pulls, it replaces AWX and manual terminal execution with a polished dashboard for scheduling, access control, notifications, and execution history across mixed infrastructure automation environments.

Promise-based Node.js ORM

Mature, promise-based ORM for Node.js supporting PostgreSQL, MySQL, MariaDB, SQLite, and SQL Server. Features model definitions with validations, eager/lazy loading, transactions, migrations, raw queries, and lifecycle hooks. Supports soft deletes, scopes, and virtual fields. One of the oldest and most battle-tested Node.js ORMs, widely used in enterprise apps though increasingly succeeded by Prisma and Drizzle in new projects.

Rust-powered coding agent and pair programmer by OVH

ShAI (Shell AI) is a CLI that brings natural language to the command line, turning plain English descriptions into executable shell commands tailored to your OS and shell. Offers command generation plus command explanation (paste an unfamiliar command, get a breakdown). Adapts syntax for macOS, Linux, and Windows across bash, zsh, fish, and PowerShell. The OVH shai variant extends further into a full pair-programming coding agent with support for multiple LLM providers.

AI-powered command-line productivity tool

ShellGPT (sgpt) is a command-line productivity tool powered by OpenAI models that generates shell commands, code snippets, and documentation directly in the terminal. Integrates with Bash, Zsh, PowerShell, and CMD; places AI-suggested commands into the terminal input via hotkeys. Supports persistent chat sessions, a REPL mode, and custom Python functions for extending capabilities. Accepts stdin and arguments for pipe-based workflows where command output can be piped to the AI.

Hunt down social media accounts by username across 400+ platforms

Sherlock is a Python CLI tool that searches for a given username across 400+ social networks and websites simultaneously. It is widely used in OSINT investigations, security audits, red teaming exercises, and digital footprint analysis. Sherlock is included in Kali Linux and Parrot Security distributions and has over 76,000 GitHub stars, making it one of the most popular open-source security tools.

YC-backed cloud deployment platform for Rust and Python applications

Shuttle is a YC-backed cloud deployment platform that simplifies deploying Rust and Python backend applications. Developers annotate their code with Shuttle macros to declare infrastructure needs like databases, caches, and secrets, and Shuttle provisions the resources automatically on deployment. Features instant deployment, automatic HTTPS, and infrastructure-from-code. Over 6,100 GitHub stars.

Visual agent builder with 1000+ integrations

Sim is an open-source platform for building, deploying, and orchestrating AI agents with a visual workflow editor. Connects 1,000+ integrations and LLMs with drag-and-drop canvas design, AI-assisted Copilot for generating nodes from natural language, and built-in knowledge base for RAG. Trusted by 100K+ builders. Includes 11 pre-built workflow templates for quick deployment.

Run AI workloads on any cloud with automatic cost optimization

SkyPilot is an open-source framework for running LLMs, AI, and batch jobs on any cloud with automatic cost optimization. It supports AWS, GCP, Azure, Lambda Cloud, and more, automatically selecting the cheapest available GPUs and managing spot instance preemption. Features include multi-cloud job scheduling, managed spot jobs with automatic recovery, and cluster autoscaling with 6,000+ GitHub stars.

Package manager for MCP servers and agent skills

Smithery is a CLI tool and registry for discovering, installing, and managing MCP servers and agent skills. It lets developers search thousands of available servers, install them with one command, inspect available tools, and connect their AI coding agents to external capabilities through the Model Context Protocol standard.

Hugging Face's lightweight agent framework

smolagents is Hugging Face's lightweight agent framework for building AI agents that can use tools, write and execute code, and collaborate in multi-agent setups. Designed for simplicity with minimal abstractions — agents are just LLMs that write Python code to orchestrate tool calls rather than using JSON-based function calling. Supports any LLM provider, integrates with Hugging Face Hub for sharing tools and agents, and runs with as few as 1,000 lines of core library code.

ByteDance high-performance JSON library

Sonic is ByteDance's blazingly fast JSON serialization library accelerated by JIT compilation and SIMD instructions. It achieves 3x faster throughput than Go's standard library while using 75% less memory and 99% fewer allocations. Drop-in compatible with encoding/json, it handles both simple Marshal/Unmarshal operations and streaming APIs for high-throughput services processing millions of events.

Self-hosted code understanding for humans and agents

Sourcebot is a self-hosted code intelligence platform that helps developers and AI agents understand large codebases through intelligent search, navigation, and inline-cited answers. Deployed as a Docker container with MCP server support, it indexes thousands of repositories without source code leaving your infrastructure.

Google Zanzibar-inspired authorization database

SpiceDB is an open-source authorization database inspired by Google's Zanzibar system, providing relationship-based access control (ReBAC) at scale. It defines permissions through a schema language that models relationships between users, resources, and roles, then evaluates authorization checks in single-digit milliseconds. Used by companies like Netflix and GitHub, SpiceDB handles millions of permission checks per second.

Build stellar documentation with Astro

Starlight is an open-source Astro-based documentation theme from the Astro team that produces fast, accessible, SEO-friendly docs sites with minimal config. Ships dark mode, full-text search via Pagefind, versioned navigation, i18n, auto-generated sidebars, and beautiful defaults out of the box. Ideal for open-source projects, product docs, and technical handbooks that want first-class performance.

State-machine guardrails for controlling which tools AI coding agents can use at each phase.

Statewright is a guardrail layer for AI coding agents that uses explicit state machines to control what an agent can do at each stage of a workflow. Instead of relying only on prompt instructions, teams can model phases such as plan, implement, test, and review, then constrain tool access for clients like Claude Code, Codex, Cursor, opencode, and related MCP workflows.

Open-source browser infrastructure for AI agents at scale

Steel is an open-source browser API purpose-built for AI agents, providing managed headless browser sessions with anti-bot bypass, proxy rotation, CAPTCHA solving, and session persistence. It handles the infrastructure layer that browser automation agents like Browser Use and Stagehand run on top of. Self-hostable or available as a cloud service. Over 6,000 GitHub stars.

UI component workshop

Storybook is an open-source workshop for building, documenting, and testing UI components in isolation. Render every visual state of React, Vue, Angular, Svelte, or Web Components, write interaction tests, visual regression tests, and accessibility checks, and publish a living design reference. Trusted by thousands of teams including GitHub, Airbnb, Shopify, and Microsoft as their single source of UI truth.

AWS open-source SDK for building model-driven AI agents

Strands Agents is an open-source SDK from AWS that takes a model-driven approach to building AI agents. Developers define a prompt, model, and tools, and the LLM handles planning and orchestration autonomously. Supports Amazon Bedrock, Anthropic, OpenAI, Gemini, Ollama, and more. Powers Amazon Q Developer and AWS Glue in production. Available in Python and TypeScript with native MCP support.

Open-source headless CMS for developers

Strapi is the leading open-source headless CMS with 65K+ GitHub stars providing a customizable API-first content management system. Auto-generates REST and GraphQL APIs from content types defined through a visual builder. Features role-based access control, media library, internationalization, draft/publish workflow, and a plugin marketplace. Built with Node.js and supports PostgreSQL, MySQL, SQLite, and MariaDB. Self-hostable with Strapi Cloud also available.

Mutation testing framework to validate test quality

Stryker Mutator is an open-source mutation testing framework for JavaScript, TypeScript, C#, and Scala that measures the real effectiveness of your test suite. It introduces small code mutations and checks whether tests catch them, revealing gaps that line coverage metrics miss. Supports incremental mode for CI/CD integration.

Open-source generalist AI agent for browser and code tasks

Suna is an open-source generalist AI agent that can autonomously browse the web, write and execute code, manage files, and interact with external services. It features a real-time browser automation engine, an isolated code execution sandbox, and integrations with popular APIs. Designed as an open-source alternative to commercial AI agent platforms. Over 9,000 GitHub stars with rapid community growth.

AI agent safety SDK with guard, redact, and scan modules

Superagent is an open-source AI agent safety SDK that provides runtime protection through four modules: Guard for detecting prompt injections and unsafe tool calls, Redact for removing PII and secrets, Scan for analyzing repos against AI-targeted attacks, and Test for red-team evaluations. It works with any LLM provider and includes open-weight guard models from 0.6B to 4B parameters with 50-100ms latency for real-time protection.

Open-source Firecracker sandboxes for long-running AI agents

Superserve is an open-source sandbox infrastructure layer for AI agents that need durable computers instead of short-lived shells. It runs isolated Firecracker microVMs, supports pause, resume, snapshot, fork, preview URLs, MCP connectivity, SDK/API control, Docker workloads, and self-hosting, while the hosted service adds pay-as-you-go agent sandboxes for teams.

Reusable computer vision tools for developers

Supervision is an open-source Python toolkit by Roboflow providing reusable CV utilities for detection, tracking, annotation, and dataset management. It works with any model including YOLO and Hugging Face via a standardized Detections class. Features include 20+ annotators, ByteTrack object tracking, zone counting, speed estimation, and dataset conversion between COCO, YOLO, and Pascal VOC formats.

Production-ready React Suspense and error handling

TypeScript library extending React Suspense API with declarative components and hooks for production applications. Provides ErrorBoundary with selective error catching via shouldCatch, SSR-safe Suspense with clientOnly prop, Delay component preventing loading flashes, ErrorBoundaryGroup for coordinated resets, and data fetching components including SuspenseQuery and SuspenseInfiniteQuery. MIT licensed by Toss with three years of active development.

API design and documentation standard

Industry-standard specification for defining RESTful APIs with a comprehensive ecosystem of tools. OpenAPI Specification (formerly Swagger) describes endpoints, parameters, responses, and authentication in YAML/JSON format. Swagger UI generates interactive API documentation, Swagger Editor provides a visual spec editor, and Swagger Codegen generates server stubs and client SDKs in 40+ languages. The foundation of API-first development workflows used by millions of developers worldwide.

Multi-agent orchestration with 10+ swarm patterns

Swarms is an enterprise-grade multi-agent orchestration framework with 6,100+ GitHub stars that provides 10+ swarm patterns including sequential, concurrent, hierarchical, mixture-of-agents, and graph-based workflows. The SwarmRouter lets teams switch between orchestration strategies by changing a single parameter. It supports MCP for tool integration, multi-model providers via Anthropic, OpenAI, and local models, and includes an AutoSwarmBuilder that generates agents from task descriptions.

Open-source library for generating synthetic tabular data

Synthetic Data Vault (SDV) is an MIT-backed open-source Python library for generating synthetic tabular, relational, and time-series data. It learns statistical patterns from real datasets and produces synthetic versions that preserve distributions, correlations, and referential integrity. Supports single-table, multi-table, and sequential data with built-in privacy and quality metrics.

Open-source GUI for managing AI coding agents with your own API keys

Unified desktop interface for Codex and Claude Code with a model selector dropdown. Features a git-integrated sidebar, parallel task and thread management, chat and plan modes, and customizable agent access levels. Run via desktop app or npx for instant access. Brings visual project management to terminal-based AI coding agents without sacrificing their command-line power.