thoughtbot/factory_bot

Node.js Best Practices, maintained at goldbergyoni/nodebestpractices, is a curated checklist of more than 80 recommendations for building Node.js applications, organized into eight categories from project architecture to Docker. Each entry combines a short recommendation with an explanation of the risk of skipping it and a link to a deeper write-up, rather than being a plain list of links.

Playwright is Microsoft's framework for automating and testing the web, hosted at microsoft/playwright under an Apache-2.0 license. Chromium, Firefox, and WebKit are all controlled through one API, shipped as five entry points — Playwright Test, a CLI, an MCP server, a Library, and a VS Code extension — covering everything from end-to-end suites to AI-agent browser control.

Hoppscotch is an open-source API development ecosystem, built in TypeScript and licensed under MIT, that serves as a web-based client for interacting with APIs. It offers PWA, desktop, and CLI options via add-ons, positioning itself as an alternative to commercial tools like Postman. It handles a wide range of protocols including HTTP (supporting all standard and custom methods), WebSocket, Server-Sent Events, Socket.IO, MQTT, and GraphQL. Developers can define requests with various authorization types (Basic, Bearer, OAuth 2.0, OIDC), custom headers, and parameters, and craft request bodies in formats like FormData or JSON. The tool includes features like Pre-Request Scripts and Post-Request Tests using JavaScript, environment variables, and organized collections with nested folders for managing API calls. For collaboration, it supports teams with shared collections, role-based access, and workspaces, along with a proxy mode to address CORS issues or access non-HTTPS endpoints. It also provides cloud sync for data across devices and a customizable UI with theming and keyboard shortcuts.

Public APIs is a community-curated GitHub repository listing free, publicly accessible APIs across a wide range of categories, with auth type, HTTPS, and CORS noted for each entry. It's a browsable reference, not a library to install.