Directory

Open-source API client that runs in the browser or as a desktop app, supports REST, GraphQL and realtime protocols, and can be self-hosted for teams

Feature-rich terminal emulator for macOS with split panes, profiles, triggers, search, tmux integration and a Python scripting API

JavaScript testing framework created at Meta with built-in assertions, mocking, snapshot testing and parallel test execution

Dynamically typed, JIT-compiled language for numerical and scientific computing that aims to combine high-level syntax with compiled-code speed

Lightweight open-source JavaScript library for interactive tile-based web maps with markers, vector layers and a large plugin ecosystem

Open-source functional programming language and interactive theorem prover with dependent types, the Mathlib mathematics library and VS Code tooling, stewarded by the Lean FRO

Open-source vector-tile map renderers for web (GL JS) and native platforms, forked from Mapbox GL and governed by a community organisation

JavaScript library that renders flowcharts, sequence, class, state, ER, Gantt and other diagrams from a Markdown-like text syntax

Python static site generator for project documentation that builds a navigable site from Markdown files and a single YAML configuration

Open JSON-RPC standard for connecting AI applications to tools, data and prompts through servers, now stewarded under the Linux Foundation with SDKs in many languages

Modal, terminal-based text editor forked from Vim with Lua configuration, a built-in LSP client and Tree-sitter parsing

React framework from Vercel for full-stack web applications with file-based routing, server components, server-side rendering, static generation and API route handlers

Server-side JavaScript runtime built on the V8 engine, governed by the OpenJS Foundation, with npm as its package ecosystem

Vendor-neutral, machine-readable standard for describing HTTP APIs in JSON or YAML, maintained by the OpenAPI Initiative under the Linux Foundation

Universal document converter that translates between Markdown, LaTeX, HTML, DOCX, EPUB, Typst, Jupyter and dozens of other formats, with citeproc and Lua filters

Microsoft's browser automation and end-to-end testing framework driving Chromium, Firefox and WebKit from one API in TypeScript, Python, Java and .NET

Posit's multi-language data-science IDE built on Code OSS, with first-class R and Python consoles, variables and plots panes, under the Elastic License 2.0

Commercial API platform for designing, testing, documenting and monitoring HTTP and other APIs through a desktop and web client with cloud-synced workspaces

Opinionated code formatter for JavaScript, TypeScript, CSS, HTML, Markdown, YAML and more that reprints code from its syntax tree with few options

TypeScript ORM with a declarative schema language, generated type-safe client and migration tooling, from the company that also offers Prisma Postgres and related hosted services

Node.js library from the Chrome team for controlling Chrome and Firefox over the DevTools Protocol or WebDriver BiDi, used for scraping, screenshots, PDFs and testing

Python IDE from JetBrains with deep static analysis, refactoring, debugging, scientific tooling and a unified free core with a paid Pro tier

Python data-validation library using type hints to parse, validate and serialize models, with a Rust core; the schema layer behind FastAPI and many LLM SDKs

Python testing framework with plain assert statements, fixtures, parametrization and a large plugin ecosystem, the de facto standard for Python test suites