Open source. Open possibilities.

A curated list of programming tutorials for learning by building real applications from scratch, organized by programming language and covering compilers, kernels, games, web and mobile apps.

date-fns is a modular JavaScript date utility library with 200+ pure functions for parsing, formatting, comparing and manipulating dates in browsers and Node.js. It uses native Date objects, is written in TypeScript, supports tree-shaking and dozens of locales, and adds first-class time zone support in v4.0.

ytDownloader is a cross-platform desktop GUI for downloading video and audio from hundreds of sites via yt-dlp, with playlist support, subtitles, range selection, hardware-accelerated compression, multiple themes, and no ads or trackers.

A desktop pet for Windows (macOS beta): a pixel cat or dog that sits in a transparent, click-through overlay, reacts to typing, scrolling, petting and cursor play, and delivers break timers, reminders and optional mail or calendar alerts. All sprites and sounds are generated in code.

GeeksPulse is a free, ad-free developer news aggregator that curates 50 hand-picked RSS feeds across 11 categories into a fast static site with a cyberpunk UI, AI summaries, bookmarks and keyboard shortcuts.

Outline is a fast, real‑time collaborative knowledge base for teams. Built with React and Node.js, it supports markdown, offers hosted and self‑hosted deployments via Docker, and includes extensive documentation, translation, and contribution guidelines.

Wails is a framework for building desktop applications with Go and web technologies, bundling Go backend code and an HTML/JS/CSS frontend into a single binary using native rendering engines instead of an embedded browser.

Frontend for Tuleva's Estonian pension onboarding web client, built with React and TypeScript, featuring migration from Redux to React Query and modern testing practices.

BentoPDF is a privacy-focused, client-side PDF toolkit that allows users to manipulate, edit, and convert PDF files directly in the browser without server-side processing.

A curated collection of single-file cheatsheets covering popular programming languages, backend and frontend frameworks, databases, and development tools, with a website directory and open contribution via pull requests.

Flux-Chat is a chat application built with Node.js, Express, ReactJS, Flux, MongoDB, and Gulp. The README covers a demo link, npm-based setup/build/start, gulp watching, deployment, testing with Testem, and configuration files.

Refine Core is an open-source React meta-framework for building CRUD-heavy enterprise apps like admin panels, dashboards and internal tools. It offers a headless architecture with hooks and components for auth, access control, routing, networking, state management and i18n, plus connectors for 15+ backend services.

Hyper is an open-source terminal emulator built on open web standards, offering an extensible, customizable command-line experience with plugins and themes.

Immich is a high-performance self-hosted photo and video management solution featuring mobile and web interfaces.

README-described Node.js bot and smart contract for ETH/USDC DeFi arbitrage with flash loans. It scans prices on Chainlink, Uniswap V2, SushiSwap, Curve and Balancer, supports Aave, dYdX, Uniswap V3 and Balancer loans, and uses a 0.9% price-difference threshold.

Code随想录 (LeetCode-Master) is a structured LeetCode study plan covering data structures and algorithms, with 200+ curated problems, detailed图文 solutions, and video lectures, supporting C++、Java、Python and other languages.

A Node.js command-line bot that watches ETH/USDC prices across DeFi venues and, when the spread passes 0.9%, drives a flash-loan arbitrage cycle through a smart contract. The README covers wallet setup, menu options, fees and risk notes.

Free index of Chinese programming books covering operating systems, AI, Web, algorithms, and various programming languages, with community contributions.

Discourse is an open-source community platform designed for hosting discussion forums with real-time chat and extensive customization options.

FlashLoanArbitrage is a Node.js command-line bot that scans ETH/USDC prices across five DeFi price sources and triggers a flash-loan arbitrage routine when the spread reaches 0.9%. It offers Aave, dYdX, Uniswap V3 and Balancer as loan sources and stores a generated or imported wallet key locally in wallet.json.