Open-source alternatives to Openjdk Jdk

Crafting Interpreters is a comprehensive resource for building a complete programming language from scratch. It provides a structured guide to the fundamental components of language implementation, including lexing, parsing, and the design of execution engines. The project demonstrates two distinct approaches to language execution: a tree-walking interpreter that evaluates source code by traversing its abstract syntax structure, and a stack-based virtual machine that compiles code into custom bytecode for execution. These implementations are supported by core runtime mechanisms such as lexica

Processing is a creative coding environment and Java graphics library designed for writing visual sketches that produce interactive 2D and 3D graphics and animations. It runs on the Java Virtual Machine, using an OpenGL-based hardware-accelerated rendering pipeline, and operates on a sketch-based execution model where programs run as continuous loops of setup and draw functions with event-driven input handling for keyboard, mouse, and window interactions. The environment distinguishes itself as a cross-platform sketch tool that runs visual programs unchanged on desktop, web, Android, and Rasp

This project provides a comprehensive framework for creating, managing, and executing educational programming challenges. It includes standardized systems for authoring instructional content, defining test cases, and structuring documentation to ensure consistent learning outcomes. The platform supports a wide range of programming languages through dedicated execution environments that handle compilation, dependency management, and automated testing. The infrastructure facilitates both local and remote development workflows, offering command-line utilities for testing code without requiring v

Manage your Java environment

FoldCraftLauncher is a Java game launcher for Android that provides a mobile runtime environment for executing various game versions and snapshots. It functions as an Android game environment that manages game instances, save files, and graphical renderer plugins. The project includes a Java runtime manager to bundle or import multiple Java versions, ensuring compatibility across different software releases. It features a virtual input mapper that simulates mouse and keyboard events by translating touch screen interactions and gyroscope data into desktop-style control signals. The system pro

j2objc is a source-to-source compiler and transpiler that converts Java source code into Objective-C. It functions as a cross-platform logic porter, allowing application logic and data models written in Java to be shared and executed on iOS. To support this translation, the project provides an Objective-C implementation of core Java classes and APIs to emulate the Java runtime environment. The system includes specialized translation for Java libraries and provides mapping for dependency injection and static analysis annotations to preserve metadata. It also enables the conversion of JUnit tes

Clojure is a general-purpose, functional programming language hosted on the Java Virtual Machine. It is a homoiconic S-expression language that represents programs as nested data structures, allowing code to be manipulated and evaluated as data. The project provides a framework for JVM interoperability, enabling the invocation of Java methods and integration with other JVM-based languages. It distinguishes itself through a persistent data structure library that uses bitmapped vector tries to manage immutable collections and a programmatic REPL for interactive software development and real-tim

SDKMAN is a command-line utility for installing, tracking, and managing multiple versions of software development kits on Unix systems. It functions as a software installer and environment manager that automates the downloading and configuration of development tools for Linux and macOS. The tool enables the installation of parallel SDK versions on a single system and provides the capability to toggle between them to change the active environment for a shell session. It specifically facilitates the setup of Java development environments, including the management of various Java Development Kit

JRuby is a Ruby language implementation that runs on the Java Virtual Machine. It serves as a cross-language runtime and execution environment, allowing Ruby code to run on the JVM and share memory with Java applications. The project functions as a bridge between Ruby and Java, enabling Ruby scripts to call Java classes and libraries directly. It also provides a mechanism to embed a Ruby interpreter into Java applications to allow for dynamic scripting. The runtime leverages the JVM for system scalability and ensures a consistent execution environment across different operating systems.

GitBucket is a self-hosted Git hosting platform and forge designed for managing private repositories. Built with the Scala language, it provides a web interface for version control and is implemented as a server compatible with the GitHub API to ensure integration with existing third-party tools. The platform allows for customization of the version control environment through a plugin-based extension model, enabling the installation of third-party plugins to add specialized features. Its capability surface covers software project management via integrated issue trackers, pull requests, and w

This project is a comprehensive educational repository designed to help developers master the core mechanics, runtime behaviors, and browser-native capabilities of the JavaScript language. It provides a structured knowledge base that covers fundamental language features, such as prototype-based inheritance and event-loop-based concurrency, alongside advanced topics like JIT-compiled execution and memory management. The repository distinguishes itself by offering deep-dive technical guides that bridge the gap between abstract language concepts and practical browser implementation. It features

This project is a suite of basic command line utilities rewritten in Rust, providing a cross-platform implementation of POSIX shell utilities. It serves as a portable CLI toolset designed to run across different operating systems and architectures. The implementation includes a WebAssembly shell environment, which allows these essential command line tools to be executed directly within a web browser without requiring a local installation. The toolset covers a broad range of system capabilities, including filesystem operations, text processing and stream editing, and system administration too

LiteIDE is a cross-platform integrated development environment designed for writing, compiling, and debugging Go source code. It functions as both a code editor with syntax highlighting and a build tool orchestrator that manages toolchains, environment profiles, and cross-compilation targets. The environment is modular and extensible, supporting third-party plugins and custom keyboard mapping to tailor the coding workflow. It provides an integrated interface for external debuggers to inspect program execution and state. The platform covers a broad range of development capabilities, including

Luvit is an event-driven runtime for Lua that integrates libuv to provide non-blocking I/O and asynchronous system operations. It functions as an asynchronous network framework and execution environment that leverages Just-In-Time compilation for high-performance script processing. The platform enables the distribution of network traffic across multiple CPU cores through a TCP cluster manager that shares socket handles among child processes. It provides specialized capabilities for building HTTP servers by decoding incoming request streams and encoding responses via a stream processor. The r

c3c is the compiler for the C3 programming language, transforming source code into executable binaries, static libraries, or dynamic libraries using an LLVM backend. It implements a system based on result-based error handling, scoped memory pooling, and a semantic macro system. The compiler provides first-class support for hardware-backed SIMD vectors that map directly to processor instructions and enables runtime polymorphism through interface-based dynamic dispatch. The project covers a broad set of low-level capabilities, including manual and pooled memory management, inline assembly inte

This project is an NGINX module that embeds the Lua scripting language directly into the server environment. It functions as a request processor and response filter, enabling the execution of scripts to handle HTTP requests, generate dynamic content, and manage server behavior without external application calls. The module provides a shared memory dictionary and cache manager, allowing data to be stored and retrieved across all active worker processes. This capability supports the collection of high-performance server metrics and the synchronization of information across concurrent processes.

gradle-retrolambda is a Gradle plugin and bytecode transformer designed to enable the use of modern Java lambda expressions in legacy Java and Android runtime environments. It functions as a backporting tool that ensures modern functional programming syntax remains compatible with older virtual machines. The project transforms compiled class files to make them compatible with Java 6 and 7 environments. This allows for the use of modern Java features in projects that must maintain backward compatibility with older API levels and legacy Android devices. The tool integrates into the Gradle buil

OpenGrok is a Java-based source code search engine and indexer designed to process large source trees and binaries into a searchable index. It functions as a version control browser, allowing for the exploration and searching of revision histories integrated with version control systems. The system provides symbol-based cross-referencing to link code definitions and usages, enabling navigation across a codebase. It utilizes an inverted-index search engine to perform full-text retrieval of source code. The application supports periodic source synchronization and reindexing to keep local data

Dolphin is a software environment that simulates GameCube and Wii console hardware, allowing users to execute game discs and digital software on modern computing platforms. It functions by translating original console processor instructions into native host machine code at runtime and intercepting low-level graphics commands to render them through modern graphics APIs. The project distinguishes itself through a comprehensive netplay engine that enables online multiplayer for local games by synchronizing game states and input timing across remote instances. This system enforces deterministic e

Brave is a privacy-centric web browser built on the Chromium engine. It functions as a cross-platform navigation tool designed to protect user data by automatically blocking trackers and advertisements by default. The browser distinguishes itself through integrated search capabilities that allow for programmatic control over query execution and data retrieval. It provides a platform for custom search engine development, enabling users to apply specific ranking rules, filter content based on geographic or temporal constraints, and enrich results with real-time structured data. Beyond its core

Distroless provides a collection of security-hardened, minimal base container images designed to reduce attack surfaces by excluding non-essential system utilities, package managers, and shells. These images are constructed to contain only an application and its specific runtime dependencies, enforcing the principle of least privilege by configuring environments for non-root execution. The project distinguishes itself through a focus on supply chain integrity and reproducible builds. It utilizes declarative build configurations to track package versions and validates container image integrity

This project is a garbage collection library and memory allocator for C and C++ that provides automatic reclamation of unreachable objects. It functions as a memory management system that can replace standard allocation functions to automate memory reclamation without requiring source modification. The system is distinguished by its ability to perform incremental and generational garbage collection to reduce application pauses, as well as parallel collection to distribute tracing across multiple CPU cores. It includes a specialized string manipulation library that uses shared structures to en

CoreCLR is a runtime environment that manages the execution, memory, and basic types for applications built on the .NET platform. It serves as a managed execution environment that handles low-level system interactions and provides primitive data types for high-level application code. The project functions as a JIT compilation engine and a garbage collected runtime. It translates intermediate language into machine code at runtime for execution on specific hardware and automatically reclaims unused memory to prevent leaks. The system covers broad capability areas including managed code executi

Duktape is an embeddable JavaScript engine and portable scripting runtime designed for integration into C and C++ applications. It functions as a lightweight ECMAScript runtime that provides a C-JavaScript bridge for exchanging data and invoking functions between native code and a script execution environment. The engine includes an ECMAScript bytecode compiler that allows for the serialization and caching of compiled functions to disk to reduce application startup time. It organizes script dependencies using a CommonJS-compliant module loader. The runtime covers a variety of capabilities in

Cello is a programming language extension for C that provides a higher-level implementation of the language. It integrates an object-oriented framework, an automated garbage collection system, and a runtime reflection library to enable dynamic type inspection. The project implements a structured system for object orientation within C, including support for classes, type classes, and polymorphism. It includes a runtime exception handling system to intercept execution errors and initiate recovery procedures. The framework further provides generic programming capabilities for creating reusable

Firefox is a cross-platform web browser engine designed to render web content, execute JavaScript, and manage secure browsing sessions. It utilizes a multi-process isolation architecture that distributes browser tasks across independent operating system processes to ensure stability and prevent site-specific failures from impacting the entire application. The engine incorporates a sandboxed execution environment to restrict web content and untrusted scripts to isolated memory compartments, enforcing security policies that prevent unauthorized access to system resources. The project distinguis

Keras is a high-level deep learning framework designed for constructing and training neural networks through the composition of modular, functional layers. It serves as a comprehensive modeling toolkit that provides standardized procedures for defining, evaluating, and deploying complex architectures. By utilizing a directed acyclic graph approach, the framework allows users to build intricate models with multiple inputs, outputs, and shared layers, ensuring consistent numerical execution through functional state management. The project distinguishes itself as a multi-backend machine learning