Open source
Open code, data, or methods that support learning, reuse, and remixing.
187 curated websites
All websites Academic Research Online Learning Practical Tools Creative Tools Explore the World Developer Tools Fun & Games Cultural Heritage Science Exploration Health & Living Career Development Shopping & Deals Social & Community Design Inspiration
Academic Research
1 websites
Online Learning
4 websites
ScratchA free block-based coding platform created at the MIT Media Lab and now run by the nonprofit Scratch Foundation. Build games, animations, and stories in the browser and share them with a global creative community.
MonkeytypeA free, open-source typing test and practice website known for its minimal design and unusually deep customization, with multiple test modes, hundreds of language word lists, and optional accounts for tracking progress.
freeCodeCampA donor-supported nonprofit offering free interactive coding courses, project-based certifications, a tech publication and a community forum — all content and certificates free.
ExercismA free, ad-free coding practice and mentoring platform with 83 language tracks and 8,600+ exercises. Solve in the browser or via CLI, get automated analysis, and request free mentor feedback. Run by a UK not-for-profit; account required.Practical Tools
3 websites
PairDropOpen-source, browser-based file transfer: devices on the same network discover each other automatically and send files peer-to-peer over WebRTC; pairing and temporary rooms extend transfers across networks. No signup, no installation.
Open Food FactsA crowdsourced food database where a barcode scan returns ingredient lists, nutrition tables and Nutri-Score style ratings; everything is published under the ODbL license by a French nonprofit.
Zen BrowserA free, open-source Firefox-based desktop browser (MPL-2.0) maintained by a volunteer community. Built around vertical tabs, with Workspaces, Compact Mode, Split View and Glance; no telemetry; funded by donations. Still officially beta.Creative Tools
5 websites
ExcalidrawAn open-source virtual whiteboard with a hand-drawn feel — sketch diagrams for free without signing up, with real-time collaboration and end-to-end encryption.
TypstTypst is a markup-based typesetting system and collaborative online editor from a Berlin team, matching LaTeX's power with simpler syntax, instant preview, and helpful errors; the compiler is open source under Apache-2.0.
Google FontsGoogle's free, open-source font library, launched in 2010: 1,946 font families as of 2026-09-02 under libre licenses, free for commercial use via embedding, download, or self-hosting, plus 3,900+ Material Symbols icons.
tldrawA free online whiteboard that works the moment you open it: infinite canvas, hand-drawn strokes, no account needed, saved in the browser. It also showcases the source-available tldraw SDK behind ClickUp Whiteboards and other products.
RiveRive is an interactive animation platform: a web editor for design, animation and state-machine logic, plus MIT open-source runtimes playing .riv files on iOS, Android, web, Flutter, Unity, Unreal. Free editor; exports from $9/seat/month.Explore the World
2 websites
OpenStreetMapOpenStreetMap (OSM) is a free, editable map of the world built by volunteers, with all data published under the open ODbL license. The official site is a reference map, a search and routing tool, and the gateway to the data.
WikivoyageFree, volunteer-written travel guide hosted by the Wikimedia Foundation, covering destinations, itineraries, and phrasebooks anyone can edit. Forked from Wikitravel in 2006, a Wikimedia project since 2013, in 27 language editions.Developer Tools
9 websites
IT ToolsAn open-source, free collection of 86 online tools for developers and IT professionals: hashing, encoding, format conversion and network calculators, all running in the browser. No signup; self-hostable via one Docker command.
GitHubThe largest code-hosting and collaboration platform, launched in April 2008 and a Microsoft subsidiary since 2018; as of 2026-09-02 it serves 225M+ developers and 800M+ repositories, with free repos plus Actions and Copilot.
RSSHubAn open-source RSS generator created by DIYgod in 2018 that turns websites without native feeds into standard RSS sources; the code is on GitHub under AGPL-3.0, with an official demo instance and encouragement to self-host.
MDN Web DocsFree, open-source web platform documentation maintained by Mozilla: HTML, CSS, JavaScript, Web APIs, and HTTP, with per-page browser compatibility tables. Online since 2005, edited on GitHub with Open Web Docs and volunteers.
roadmap.shA community-maintained collection of developer learning roadmaps: 80+ career and technology paths as clickable skill trees, each node pairing a brief with curated links; free, with content updates flowing through a public GitHub repository.
WarpWarp is an open-source, Rust-based agentic development environment: a GPU-accelerated terminal with built-in AI coding agents and a code editor for macOS, Windows, and Linux. The terminal is free, no account needed; agents use credits.
SupabaseSupabase is an open-source Postgres backend platform (BaaS): a full database with auto REST/GraphQL APIs, plus auth, storage, realtime, edge functions, and vector search. Free tier; Pro from $25/org/month; Apache-2.0, self-hostable.
ZedZed is a fast, open-source code editor in Rust from Zed Industries, founded in 2021 by the creators of Atom and Tree-sitter. Built for speed, real-time multiplayer collaboration, and model-agnostic AI. Free editor; hosted AI from $10/month.
PlausibleOpen-source, privacy-first web analytics from Estonia's Plausible Insights — no cookies, no personal data, a lightweight script, pageview-based pricing, and a free self-hosted edition.Fun & Games
3 websites
Online-Go.com (OGS)A free online Go (baduk) server in the browser: real-time and correspondence games, spectating and game study, roughly 59,000 user-made tsumego puzzles, an interactive beginner course and tournaments, with an AGPL-licensed web client.
LichessA free, ad-free, open-source online chess platform with games at every time control, 8 variants, tactical puzzles, engine analysis, tournament broadcasts and collaborative study tools, run by a French non-profit association.
MusicBrainzAn open music encyclopedia run by the nonprofit MetaBrainz Foundation — a volunteer-maintained structured music metadata database whose core data is public domain (CC0), with a free API, full data downloads, and the Picard tagging app.
