Open-source alternatives to Java

This project is a Java-based e-commerce management system and educational project suite. It serves as a backend framework for building online shopping platforms, utilizing a model-view-controller architecture to decouple user interfaces from business logic and data models. The system implements a structured web application framework that integrates relational databases to track product inventories, user accounts, and customer purchase transactions. It features a layered architecture that separates presentation, business logic, and data access. The codebase covers several core capability area

JMComic-Crawler-Python is a high-performance asynchronous web scraper and API client designed to programmatically retrieve images and metadata from a comic hosting service. It functions as a media archiving tool for batch downloading albums and chapters, automating the process of saving content to a local filesystem. The project is distinguished by its ability to reverse server-side pixel obfuscation, using a decryption tool to reconstruct sliced and shuffled images. To maintain stable connectivity, it utilizes a network bypass utility featuring dynamic domain rotation and proxy routing to ci

CodeIgniter is a PHP web framework built on the Model-View-Controller pattern, designed for building full-stack web applications. It provides a lightweight toolkit with minimal configuration, organizing application logic into controllers, models, and views for clean separation of concerns. The framework includes a fluent query builder for constructing SQL statements programmatically, PSR-4 autoloading with namespace mapping, and a service-based dependency injection container for managing shared class instances. The framework distinguishes itself through its comprehensive set of built-in tools

Scraperjs is a JavaScript web scraping library and headless browser automation tool designed to extract structured data from both static HTML and JavaScript-rendered websites. It functions as an asynchronous scraping workflow orchestrator and a selector-based engine for transforming unstructured web content into usable data. The library distinguishes itself by managing a shared browser instance across multiple tasks to optimize resource usage and reduce startup latency. It supports custom script injection into sandboxed browser environments to manipulate the DOM or execute browser-side logic

MechanicalSoup is a Python web automation library and scraping framework designed to simulate browser sessions and navigate websites without requiring JavaScript execution. It functions as an HTML parsing tool and HTTP session manager, allowing for the programmatic retrieval of page content and the automation of web interactions. The library distinguishes itself by combining session persistence with automated form interaction. It maps user data to HTML input fields and selection boxes for programmatic submission and maintains authenticated states by managing cookies and user-agent headers acr

X-Ray is a web scraping framework and asynchronous web crawler designed to extract structured data from websites. It functions as an HTML data extractor that transforms raw page content into a defined schema using CSS-style selectors. The project implements a headless browser crawler capable of executing JavaScript to render dynamic content. It handles website content discovery through a breadth-first crawling strategy and automatic pagination discovery to traverse multi-page result sets. The framework manages web data pipelines using a concurrency-limited request queue and request rate cont

This project is a self-hosted, cross-platform instant messaging platform featuring a Go backend and a protobuf-based messaging server. It provides a unified communication suite with native clients for iOS, Android, and web, utilizing gRPC and Protocol Buffers for efficient data exchange. The system is distinguished by an extensible chatbot framework that allows for the integration of automated bots and plugins via standardized service interfaces. It supports high-availability clustering with sharded load distribution and a pluggable database backend to ensure reliability and flexible data per

Colly is a web scraping framework and concurrent crawler written in Go. It provides a system for traversing web pages, following links, and extracting structured data from HTML and XML documents. The framework includes a distributed scraping engine designed to spread data collection tasks across multiple instances to increase throughput. It ensures compliance with website owner policies by automatically reading and respecting robots.txt files. The system manages request lifecycles through domain-based rate limiting, concurrency controls, and session management via a stateful cookie jar. It s

AnyCrawl is an AI-powered data extractor, automated web crawler, and headless browser orchestrator. It serves as a web content extraction API and a gateway that connects crawling and scraping tools to language models using a standardized API protocol. The project specializes in converting unstructured website content into structured JSON or markdown optimized for AI assistants. It utilizes language models and JSON schemas to pull specific information into validated formats and provides capabilities for AI page summarization and LLM-optimized content extraction. The system manages comprehensi

MallChat is an e-commerce backend system and real-time messaging platform. It provides a server-side infrastructure for managing online stores, including integrated shopping carts, order processing, and payment workflows. The system features a WebSocket chat server for instant customer communication and a content moderation engine that uses pattern matching to block sensitive language. It integrates large language models to provide automated conversational AI chatbots for customer support and product recommendations. Identity management is handled through a token-based authentication system

Skateshop is a Next.js e-commerce storefront and subscription-based commerce platform. It provides a retail website featuring product catalogs, shopping carts, and checkout flows, paired with a retail store management dashboard for tracking inventory, orders, and payments. The project includes a subscription system to process recurring payments and manage tiered access to premium services. It also integrates a markdown blog engine for publishing technical content and an email marketing system to collect subscribers and distribute newsletters. The platform covers identity management through u

Digitalhippo is a full-stack TypeScript application that functions as a digital asset marketplace for selling and distributing digital products. It integrates a transaction processing system with an e-commerce admin dashboard for monitoring platform activity and overseeing product quality. The platform features a transactional email system for automated account registration and purchase confirmations, alongside an object-relational mapping data store to manage relationships between users, products, and transactions. The system covers secure user authentication, digital storefront administrat

Realtime is a real-time data distribution and synchronization engine that enables applications to stream database changes and coordinate state between clients. It functions as a synchronization layer that monitors database write-ahead logs to provide change data capture and pushes updates to authorized clients via WebSockets. The project features a real-time presence server for tracking the online status of active users and a broadcast service for sending ephemeral messages without database persistence. It organizes communication through channel-based message routing and uses a structured JSO

This project is a collection of reference implementations and practical guides for building enterprise Java applications using the Spring Boot framework. It serves as a backend project gallery and implementation guide, providing a set of architectures for common server patterns. The repository distinguishes itself through a focus on distributed system design, offering examples for global unique identifier generation, distributed caching, and full-text search. It also includes templates and examples for creating custom Spring Boot starters to encapsulate shared dependencies and configurations

This project is a full-stack web application designed for real-time messaging and user account management. It provides a platform for exchanging text messages instantly and tracking the active network status of participants to indicate availability. The application utilizes a unified JavaScript stack to handle both client-side interface rendering and server-side data processing. It features a single-page application architecture that updates the user interface dynamically without requiring full page reloads, while maintaining persistent bidirectional connections to ensure that conversations u

Devise is a flexible authentication framework for Ruby on Rails applications. It serves as a user identity management system that handles registration, sign-in, password recovery, and account confirmation. The system integrates with the Warden middleware to manage user sessions and security across various request types. The framework functions as a multi-model authentication engine, allowing for the configuration of multiple distinct user models with independent routes and access controls. It also provides a standardized interface to connect with external identity providers and third-party lo

Nakama is a distributed server framework designed for real-time multiplayer games and social applications. It provides an authoritative runtime environment for executing game logic, ensuring consistent state and cheat-resistant gameplay across diverse client platforms. The system acts as a centralized backend, managing persistent player identities, social graphs, and real-time communication channels to support complex multiplayer interactions. The platform distinguishes itself through an integrated suite of LiveOps tools that allow developers to manage game economies, schedule time-bound even

deployd is a realtime API framework and MongoDB backend as a service that allows for the creation of networked interfaces synchronizing data and events between clients and servers. It functions as a JavaScript API middleware that can be integrated with HTTP servers to provide authentication, request interceptors, and realtime capabilities. The project features a self-hosted API management dashboard for configuring resource settings, managing data collections, and monitoring server status through a web-based interface. It includes a realtime data synchronization engine that pushes live databas

jscamp is a full-stack web development and education project focused on mastering JavaScript, TypeScript, and AI integration. It provides a structured curriculum and interactive exercises covering language fundamentals, frontend engineering, and backend API development. The project distinguishes itself through the implementation of autonomous AI agents capable of complex task automation, such as modifying files, managing servers, and executing API calls. It includes advanced AI development tools for conversational querying, real-time code suggestions, and automated repository analysis to gene

This project provides a collection of instructional guides and tutorials for Android app development, native mobile application creation, and computer science education. It focuses on building native applications through step-by-step implementation, covering the development of user interfaces and the integration of system hardware and permissions. The material extends into broader technical domains, including the study of fundamental data structures and algorithms for technical interview preparation. It also covers cybersecurity fundamentals, such as identifying web vulnerabilities and implem

Gevent is a Python coroutine concurrency library and asynchronous task manager designed for high-concurrency I/O tasks. It provides a cooperative networking framework for building asynchronous TCP, UDP, and HTTP servers, as well as a WSGI web server implementation for hosting web applications. The project is distinguished by its standard library monkey-patching tool, which replaces blocking synchronous functions with cooperative versions to enable asynchronous behavior in third-party code. This allows for a cooperative multitasking workflow where the system yields execution during I/O waits t

open62541 is an open-source implementation of the OPC Unified Architecture standard, providing a complete stack for industrial automation and data exchange. It functions as both an OPC UA server and client, enabling the creation of an object-oriented address space to model physical industrial assets and their relationships. The project is designed for versatility across diverse hardware, offering a C99 library that can be deployed to both cloud servers and resource-constrained embedded environments. It distinguishes itself through a pluggable network layer and interface-based security backend

tty.js is a web-based terminal emulator and Node.js socket terminal that provides a remote shell web interface. It acts as a browser-based gateway for executing system commands and streaming command-line input and output via network sockets. The project enables persistent shell sessions, allowing active terminal processes to remain available across browser refreshes and disconnections. It includes authentication middleware and encryption to provide secure remote shell access and restrict system control to authorized users. The system covers terminal emulation with support for colors and mous

This project provides a structured boilerplate for building Node.js REST APIs, implementing clean architecture principles to isolate business logic from external frameworks and data sources. It serves as a template for organizing complex backend services by enforcing a strict separation of concerns between domain entities, infrastructure, and interface layers. The architecture distinguishes itself through a modular, plugin-based server design built on the Hapi.js framework. It utilizes a dependency injection container to decouple business logic from concrete implementations, ensuring that ser

This project is the core management framework for a security appliance, providing the primary infrastructure for firewall management, network intrusion prevention, and high-availability networking. It serves as the centralized system for controlling network security policies, filtering traffic, and administering a security appliance dashboard. The system is distinguished by its high-availability capabilities, which include synchronizing configurations and connection state tables across redundant nodes to enable automatic hardware failover. It also features a modular plugin architecture for ex

Scira is an AI-powered search and synthesis engine that uses agentic research workflows to find and organize information from the web and academic sources. The system breaks complex queries into multi-step plans and generates grounded answers with inline citations for verification. The platform distinguishes itself by executing Python code within isolated sandboxes to perform data analysis and create visual charts from retrieved data. It also implements retrieval-augmented generation to perform semantic searches across uploaded documents, including PDFs and CSV files, and integrates with clou

Asterinas is a memory-safe operating system kernel designed to prevent data races and memory corruption. It functions as a Linux-ABI compatible kernel, enabling the execution of existing Linux binaries and container workloads while providing a declarative operating system distribution model. The project distinguishes itself by acting as a virtual machine container host and a confidential computing guest OS, allowing it to run within hardware-isolated Trusted Execution Environments such as Intel TDX. It implements a minimal trusted computing base by isolating unsafe low-level operations and se