Lumina — 400+ Curated AI & Developer Tools, Free Discovery Platform

Mozilla's definitive reference for HTML, CSS, JavaScript, and every core Web API, maintained with contributions from Microsoft, Google, and Samsung. Combines structured guides, tutorials, live code examples, and browser compatibility data for thousands of features. Widely treated as the canonical documentation cited in specs, courses, and interviews.

Up-to-date browser support tables for HTML5, CSS3, JavaScript APIs, and emerging web platform features. Search any feature to see adoption across desktop and mobile browsers, with global usage percentages and notes on flags or prefixes. Essential for deciding whether a feature is safe to ship in production.

Fast, searchable aggregator of official documentation for 200+ languages, frameworks, and tools in a single consistent interface. Supports fuzzy search, offline mode via installable doc sets, and dark theme, making it ideal for quick lookups while coding. Open source and run by the freeCodeCamp community.

Community-driven guides laying out the skills, tools, and technologies to learn for paths like frontend, backend, DevOps, AI engineering, and more. Each roadmap is an interactive checklist with linked resources so you can track progress step by step. Used by millions of developers to plan careers and structured learning.

Free nonprofit learning platform with thousands of hours of interactive curriculum covering web development, Python, data analysis, machine learning, and more. Earn verified certifications through hands-on projects and practice on thousands of coding challenges. Backed by a huge YouTube channel and community forum.

A deep, well-structured guide from language basics to advanced topics like closures, prototypes, the event loop, and browser APIs. Includes annotated examples and exercises with solutions across 20+ parts. Frequently recommended as the single best free resource for mastering JavaScript.

Interactive visualizer that teaches Git branching, rebasing, cherry-picking, and remote workflows through progressive levels. You type real commands and watch commits move around a commit graph, building intuition for what happens under the hood. Includes a sandbox mode for experimenting freely.

Practical cheat sheet for recovering from common Git mistakes like committing to the wrong branch, bad commit messages, accidental resets, and messy merges. Every scenario shows both the plain-language problem and the exact commands to fix it. Hosted at dangitgit.com so you can type it quickly mid-panic.

Quick reference cheat sheets for dozens of languages, frameworks, databases, and Linux tools, all rendered as clean copy-friendly snippets. Great for grabbing exact syntax for pandas, Dockerfile, Vim, SQL joins, and more without wading through full docs.

Rapid-fire cheat sheets covering Ruby, Python, JavaScript, Bash, Vim, React, TypeScript, regex, and dozens of other tools. Concise one-liner style examples make it perfect for quick syntax reminders during daily development.