Open-source alternatives to Jruby

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

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

Opal is a Ruby frontend framework and compiler that translates Ruby source code into JavaScript. It functions as a web runtime that allows for the development of client-side web applications using Ruby instead of JavaScript. The project includes a Ruby HTML template engine that evaluates Ruby code embedded directly within markup files. It further integrates with JavaScript environments by bundling core libraries and dependencies into a distribution string for execution in a web browser. The system provides capabilities for Ruby to JavaScript compilation and the ability to encode and decode B

This project is a full-stack web framework designed for building database-backed applications through a standardized architectural pattern. It provides a comprehensive suite of integrated libraries that manage the entire request-response lifecycle, from routing incoming web traffic to rendering dynamic server-side templates. By utilizing an object-relational mapping layer, the framework allows developers to define domain models that map database tables directly to application objects, simplifying data persistence, schema migrations, and complex relationship management. The framework is distin

Hanami is a full-stack Ruby web framework and API platform designed for building maintainable applications. It centers on a modular web architecture that organizes software into independent slices to prevent monolithic growth and isolate functional units. The framework implements a clean architecture by decoupling business logic from persistence and request handling. This is achieved through a central dependency injection container for managing object lifetimes and a repository pattern mapper that separates domain entities from the persistence layer. The project further provides a Rack-compa

凹语言, The Wa Programming Language

Sinatra is a lightweight web framework for the Ruby programming language designed for building web applications and services. It provides a domain-specific language that maps HTTP verbs and URL patterns directly to executable code blocks, allowing developers to define routes and handle incoming network requests with minimal boilerplate. The framework distinguishes itself through a modular architecture that relies on a middleware pipeline to process, modify, or terminate connections. This design allows for the integration of external functionality by mixing modules into the core request-handli

The Essential Toolkit for building Internal Tools and admin panels with Ruby on Rails

The Java Development Kit is a comprehensive software development environment designed for compiling, debugging, and executing applications written in the Java programming language. It provides the core infrastructure necessary to transform human-readable source code into platform-independent bytecode and run those applications across diverse computing environments. At the center of this environment is the Java Virtual Machine, a runtime engine that executes compiled bytecode while managing memory and system resources. This architecture utilizes a stack-based virtual machine and a platform-agn

esProc is a distributed ETL framework and embedded data computation engine. It provides a structured data language for the Java Virtual Machine designed for relational queries, complex data computation, and structured data analysis. The system features a natural language data query interface that leverages large language models to translate requests into executable queries against structured datasets. It employs a domain-specific query language with a concise syntax to establish table relationships and retrieve information. The platform covers data integration across disparate relational and

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

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

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

bitcoinj is a Java library and software development kit for integrating Bitcoin blockchain functionality into applications. It provides a foundation for implementing blockchain clients and managing digital wallets, allowing for the programmatic tracking of blockchain state and transaction histories. The project includes tools for creating and maintaining keychains and wallets, supported by a command-line interface for administrative wallet management and blockchain state synchronization. The library covers core cryptographic and structural primitives, including deterministic key derivation,

Wren is an embeddable, class-based scripting language and bytecode interpreter. It provides a dependency-free virtual machine designed for integrating dynamic script execution into host applications via a C API. The language is centered on a modern object-oriented model featuring inheritance, method overloading, and first-class functions. It utilizes a concurrent fiber runtime to manage lightweight, cooperatively scheduled execution paths without relying on operating system threads. The project includes a comprehensive suite of object-oriented primitives, closure-based state capture, and a m

PythonNet is a runtime integration bridge that enables Python code to call .NET assemblies and functions within the Common Language Runtime. It serves as a set of bindings for accessing the .NET framework and its libraries from a Python environment, facilitating cross-language runtime interoperability. The project provides a mechanism for embedding a Python scripting engine directly within .NET applications. This allows for the creation of an application scripting layer where Python code is executed dynamically to provide customization and automation for the host environment. The bridge supp

This repository provides a collection of reference implementations and patterns for testing Android applications. It serves as a guide for developers to integrate standard testing libraries and frameworks into their projects, covering the full spectrum of verification from local business logic to complex interface interactions. The project distinguishes itself by demonstrating how to configure and execute tests across diverse environments, including local virtual machines and physical devices or emulators. It provides specific patterns for validating inter-application communication, automatin

Scala 3 is an open-source, statically typed programming language that compiles to JVM bytecode, combining object-oriented and functional programming paradigms. Its core identity is defined by a sophisticated type system that includes traits, generics, union types, and a dependent object type system where types can depend on runtime values through path-dependent and singleton types. The language distinguishes itself through several advanced type-level and metaprogramming capabilities. It features a contextual abstraction mechanism using given instances and using clauses for compile-time implic

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

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

Piston is a modular game engine and framework written in Rust for building two and three-dimensional graphical applications. It functions as a cross-platform windowing library and a system for managing input events and window loops across different operating systems. The project provides specialized rendering systems, including a voxel rendering engine for volumetric pixels and a skeletal animation system for deforming meshes via hierarchical bone structures. It also features an immediate mode user interface toolkit for creating responsive on-screen elements and a behavior tree AI framework t

This project is a collection of Objective-C iOS application demos and code samples. It provides implementations for core development patterns and system-level features within the iOS environment. The repository focuses on Objective-C runtime examples, demonstrating dynamic method dispatch and runtime swizzling to modify object behavior. It also includes a Core Animation UI library and samples for iOS multithreading and concurrency management. The project covers capabilities for UI animation and graphics, concurrent task coordination, and the integration of third-party services for authentica

Rhino is a Java-based JavaScript engine that implements an ECMAScript compatibility layer for execution inside a Java virtual machine. It serves as an embedded scripting engine and a scripting bridge, allowing JavaScript code to be integrated and executed within Java applications. The project facilitates direct inter-language communication by mapping Java classes and objects into a JavaScript environment. This integration enables scripts to interact with internal system services and native host objects through a dedicated mapping mechanism. The engine optimizes performance by compiling JavaS

Scala is a statically typed programming language and compiler that combines object-oriented and functional programming paradigms. It serves as a cross-platform runtime language capable of targeting the Java Virtual Machine and JavaScript to share logic between backend servers and web frontends. The project provides a functional programming framework with immutable data structures and higher-order functions to build reliable concurrent and distributed applications. It distinguishes itself through deep interoperability with Java and JavaScript ecosystems and the ability to transform code into n

FrankenPHP is a Go-based PHP runtime and application server that integrates a web server and PHP interpreter to host applications without requiring a separate process manager. It functions as a worker mode server that keeps applications in memory across requests to eliminate bootstrap overhead and a static binary bundler that packages applications and the server into a single self-contained executable. The project distinguishes itself by allowing the embedding of a PHP runtime directly into Go programs and enabling the development of PHP extensions using the Go language. It also includes a bu

ruby-build is a system for downloading, compiling, and installing specific versions of the Ruby language from source on Unix-like systems. It functions as a source compiler and version installer that manages the deployment of Ruby runtimes without relying on system packages. The tool supports custom Ruby compilation by allowing the application of patches to the source code before the compilation process begins. It also provides the ability to use external build definitions for versions not included by default. The installation pipeline includes package integrity verification using checksums

Extism is a cross-language WebAssembly plugin framework that lets applications written in any programming language load and execute plugins written in any other language. It provides a universal plugin system where host applications use idiomatic SDKs to load WebAssembly modules, call exported functions, and pass data back and forth, while plugin authors use development kits that handle memory management and host interaction so they can focus on business logic. The framework distinguishes itself through its comprehensive approach to cross-language integration, offering schema-driven binding g