Open Source Java Software - Page 29
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Java Software
Browse free open source Java Software and projects below. Use the toggles on the left to filter open source Java Software by OS, license, language, programming language, and project status.
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HTTP Kit
Clojure HTTP server/client library with WebSocket support
http-kit is a minimalist, event-driven, high-performance Clojure HTTP server/client library with WebSocket and asynchronous support. A simple, high-performance event-driven HTTP client+server for Clojure. HTTP Kit is an (almost) drop-in replacement for the standard Ring Jetty adapter. So you can use it with all your current libraries (e.g. Compojure) and middleware. Using an event-driven architecture like Nginx, HTTP-kit is very, very fast. It comfortably handles tens of thousands of requests/sec on even midrange hardware. Here is another test about how it stacks up with others. It's not only fast, but efficient! Each connection costs nothing but a few kB of memory. RAM usage grows O(n) with connections. Written from the ground-up to be lean, the entire client/server is available as a single ~90kB JAR with zero dependencies and ~3k lines of (mostly Java) code. Synchronous is simple. Asynchronous is fast & flexible. -
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Infinity For Reddit
A Reddit client for Android
A Reddit client on Android written in Java. It does not have any ads and it features a clean UI and smooth browsing experience. Infinity is a beautiful, feature-rich app that offers a smooth Reddit browsing experience. It is completely free and ad-less; you can browse Reddit without interruptions or distractions. Built by a passionate university student, Infinity is open source. -
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JDA Java Discord API
Java wrapper for the popular chat & VOIP service
JDA strives to provide a clean and full wrapping of the Discord REST api and its Websocket-Events for Java. This library is a helpful tool that provides the functionality to create a discord bot in java. Discord is currently prohibiting creation and usage of automated client accounts (AccountType.CLIENT). We have officially dropped support for client login as of version 4.2.0! Note that JDA is not a good tool to build a custom discord client as it loads all servers/guilds on startup unlike a client which does this via lazy loading instead. If you need a bot, use a bot account from the Application Dashboard. -
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Java Design Patterns
Design patterns implemented in Java
A comprehensive, community-maintained collection of design pattern implementations in Java, offering well-documented, educational examples to help developers understand and apply common architectural solutions. All designs should be as simple as possible. You should start with KISS, YAGNI, and Do The Simplest Thing That Could Possibly Work principles. Complexity and patterns should only be introduced when they are needed for practical extensibility. The design patterns are now available as an e-book. Design patterns can speed up the development process by providing tested, proven development paradigms. -
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JavaGuide
"Java Learning + Interview Guide" covers the core Java knowledge
JavaGuide is an open source knowledge base and learning resource for Java developers, created and maintained by Snailclimb. The project organizes and explains a wide range of Java-related concepts, from language fundamentals to advanced topics such as concurrency, JVM internals, distributed systems, and high availability design. It is especially popular among developers preparing for technical interviews, as it compiles common knowledge points, detailed explanations, and source code analyses that interviewers frequently explore. The repository also includes sections on computer science basics such as operating systems, networks, and data structures, along with practical guides for databases, Redis, MySQL, and MongoDB. Beyond core Java, JavaGuide covers tools like Maven, Docker, Git, and frameworks like Spring, Spring Boot, and MyBatis. Its structured approach makes it a comprehensive handbook for both beginners and experienced backend engineers. -
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Joern
Open-source code analysis platform for C/C++/Java/Binary/Javascript
Joern is a platform for analyzing source code, bytecode, and binary executables. It generates code property graphs (CPGs), a graph representation of code for cross-language code analysis. Code property graphs are stored in a custom graph database. This allows code to be mined using search queries formulated in a Scala-based domain-specific query language. Joern is developed with the goal of providing a useful tool for vulnerability discovery and research in static program analysis. -
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Juggling Lab
Juggling Lab juggling animator
Juggling Lab is an open-source juggling simulation and animation software designed to visualize juggling patterns. It allows users to create, simulate, and analyze various juggling sequences, offering both 2D and 3D visualizations. Juggling Lab is highly customizable, supporting complex patterns and siteswap notation, making it a valuable tool for jugglers, performers, and enthusiasts looking to practice or study new routines. -
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JustEnoughItems
Item and Recipe viewing mod for Minecraft
A popular Minecraft mod providing a comprehensive item recipe viewer and search functionality for in-game items. -
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Kryo
Java binary serialization and cloning, fast, efficient, automatic
Kryo is a fast and efficient binary object graph serialization framework for Java. The goals of the project are high speed, low size, and an easy-to-use API. The project is useful any time objects need to be persisted, whether to a file, database or over the network. Kryo can also perform automatic deep and shallow copying/cloning. This is direct copying from object to object, not object to bytes to object. Kryo has three sets of methods for reading and writing objects. If the concrete class of the object is not known and the object could be null. Besides methods to read and write objects, the Kryo class provides a way to register serializers, reads and writes class identifiers efficiently, handles null objects for serializers that can't accept nulls, and handles reading and writing object references (if enabled). This allows serializers to focus on their serialization tasks. -
MongoDB Atlas runs apps anywhereMongoDB Atlas gives you the freedom to build and run modern applications anywhere—across AWS, Azure, and Google Cloud. With global availability in over 115 regions, Atlas lets you deploy close to your users, meet compliance needs, and scale with confidence across any geography.
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Lottie
Render After Effects animations natively on Mobile, Web & React Native
Lottie is a wonderful library for Android, iOS, Web, and Windows that works by parsing Adobe After Effects animations that have been exported as json with Bodymovin, and then rendering these natively on mobile and on the web! Now you can have beautiful animations without engineers having to recreate everything by hand. Building animations by hand is time consuming, and other animation alternatives like Gifs and Png sequences don’t offer the same flexibility and varied features that Lottie offers. With Lottie, you can achieve exquisite animations exactly how you want, with no additional engineering effort whatsoever. Take a look at the many beautiful animation possibilities available to you on http://airbnb.io/lottie/ -
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Luaj
Lightweight, fast, Java-centric Lua interpreter
Lightweight, fast, Java-centric Lua interpreter written for JME and JSE, with string, table, package, math, io, os, debug, coroutine & luajava libraries, JSR-223 bindings, all metatags, weak tables and unique direct lua-to-java-bytecode compiling. -
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MIT Deep Learning Book
MIT Deep Learning Book in PDF format by Ian Goodfellow
The Deep Learning textbook is a resource intended to help students and practitioners enter the field of machine learning in general and deep learning in particular. The online version of the book is now complete and will remain available online for free. MIT Deep Learning Book in PDF format (complete and parts) by Ian Goodfellow, Yoshua Bengio and Aaron Courville. An MIT Press book Ian Goodfellow and Yoshua Bengio and Aaron Courville. Written by three experts in the field, Deep Learning is the only comprehensive book on the subject. This is not available as PDF download. So, I have taken the prints of the HTML content and bound them into a flawless PDF version of the book, as suggested by the website itself. Printing seems to work best printing directly from the browser, using Chrome. Other browsers do not work as well. -
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Micronaut
Micronaut Application Framework
Micronaut is a modern, JVM-based, full-stack Java framework designed for building modular, easily testable JVM applications with support for Java, Kotlin, and the Groovy language. Micronaut is developed by the creators of the Grails framework and takes inspiration from lessons learned over the years building real-world applications from monoliths to microservices using Spring, Spring Boot, and Grails. Micronaut aims to provide all the tools necessary to build JVM applications. With Micronaut you can build message-driven applications, command-line applications, HTTP servers, and more whilst for Microservices in particular Micronaut also provides distributed configuration. This is achieved by pre-computing the framework infrastructure at compilation time which reduces the logic required at runtime for the application to work. Compatible with Java, Groovy, and Kotlin, with Scala on the roadmap. -
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Mockito
Most popular Mocking framework for unit tests written in Java
Mockito downloads and instructions for setting up Maven, Gradle and other build systems are available from the Central Repository and Bintray. Mockito 3.x requires Java 8, but otherwise doesn’t introduce any breaking changes compared to the 2.x series. Mockito 2.25.0 had an important feature added for anyone using mockito-inline. In particular anyone using Kotlin (which demands using mockito-inline) and PowerMock (which exacerbates the problem even more) will want to add this to all of their test classes to avoid a large memory leak. Fancy getting world-wide visibility and building up an eternal fame of an OSS contributor? Use the latest version! Hack and experiment. Speak up at the mailing list. Mockito is a mocking framework that tastes really good. It lets you write beautiful tests with a clean & simple API. Mockito doesn’t give you hangover because the tests are very readable and they produce clean verification errors. -
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Nomulus
Top-level domain name registry service on Google Cloud Platform
Nomulus is a production-grade, open-source domain registry platform used to operate top-level domains (TLDs). It implements the core registry protocols—EPP for registrar interactions, WHOIS/RDAP for public data access—and manages the lifecycle of domain objects, hosts, and contacts. The system is built to scale and to enforce policy: pricing rules, reserved names, premium tiers, grace periods, and automated renewals are modeled explicitly. It integrates with DNS provisioning, data escrow, and billing so you can run a compliant registry end-to-end rather than stitching together separate services. Operators get admin tools for reporting, manual adjustments, and policy configuration, while registrars interact through standards-compliant channels. Nomulus treats registries as serious infrastructure: audited flows, durable storage, and clear extension points for custom policies and TLD-specific behavior. -
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OpenGrok
Fast and usable source code search and cross reference engine
OpenGrok is a fast and usable source code search and cross reference engine. It helps you search, cross-reference and navigate your source tree. It understands various program file formats and history from many Source Code Management systems. In other words it lets you grok (profoundly understand) source code and is developed in the open, hence the name OpenGrok. It is written in Java. -
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OpenLauncher
Customizable and Open Source Launcher for Android
This is an open source launcher project for Android devices that has been built completely from scratch. The main goal of this launcher is to find a healthy medium between customization and simplicity. At this point in time it implements most features required in a typical launcher but could benefit greatly from some general polish. If you would like to help out feel free to submit issues or ask about submitting a pull request with a feature you want to see in the launcher. -
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PSI Probe
Advanced manager and monitor for Apache Tomcat
Advanced manager and monitor for Apache Tomcat, forked from Lambda Probe. Generally supported versions for third-party tomcat providers align with their support but earlier versions may still work. It is advisable in every case to use only supported tomcat releases per specific vendor. Our support will only be against non-CVE releases. -
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PhotoEditor SDK
PhotoEditor SDK: A fully customizable photo editor for your app
The PESDK Android Demo is an example project showcasing how to integrate the PhotoEditor SDK (PESDK) into Android applications. PESDK is a powerful and customizable mobile photo editing framework developed by IMG.LY, enabling developers to add professional-grade photo editing capabilities to their apps. The demo illustrates features such as cropping, filtering, stickers, text overlays, adjustments, and more—all powered by a clean and user-friendly interface. It supports deep customization, allowing developers to tailor the experience to their branding and user needs while maintaining native performance. -
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Piranha
A tool for refactoring code related to feature flag APIs
Feature flags are commonly used to enable gradual rollout or experiment with new features. In a few cases, even after the purpose of the flag is accomplished, the code pertaining to the feature flag is not removed. We refer to such flags as stale flags. The presence of code pertaining to stale flags can have the following drawbacks. Unnecessary code clutter increases the overall complexity w.r.t maintenance resulting in reduced developer productivity The flags can interfere with other experimental flags (e.g., due to nesting under a flag that is always false) Presence of unused code in the source as well as the binary. Stale flags can also cause bugs. Piranha is a tool to automatically refactor code related to stale flags. At a higher level, the input to the tool is the name of the flag and the expected behavior, after specifying a list of APIs related to flags in a properties file. -
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Planetiler
Flexible tool to build planet-scale vector tilesets
Planetiler (pla·nuh·tai·lr, formerly named "Flatmap") is a tool that generates Vector Tiles from geographic data sources like OpenStreetMap. Planetiler aims to be fast and memory-efficient so that you can build a map of the world in a few hours on a single machine without any external tools or database. Vector tiles contain raw point, line, and polygon geometries that clients like MapLibre can use to render custom maps in the browser, native apps, or on a server. Planetiler packages tiles into an MBTiles (SQLite) or PMTiles file that can be served using tools like TileServer GL or Martin or even queried directly from the browser. See awesome-vector-tiles for more projects that work with data in this format. Planetiler works by mapping input elements to vector tile features, flattening them into a big list, and then sorting by tile ID to group them into tiles. -
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Quarkus MCP Server
This extension enables developers to implement the MCP server
The quarkus-mcp-server is a Quarkus extension that enables developers to implement Model Context Protocol (MCP) server features easily. It provides both declarative and programmatic APIs, simplifying the process of integrating MCP functionalities into Quarkus applications. This extension is part of the Quarkiverse, a hub for Quarkus extensions contributed by the community. -
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Reactor Netty
TCP/HTTP/UDP/QUIC client/server with Reactor over Netty
Reactor Netty offers non-blocking and backpressure-ready TCP/HTTP/UDP/QUIC clients & servers based on Netty framework. With Gradle from repo.spring.io or Maven Central repositories (stable releases only). Reactor is a fourth-generation reactive library, based on the Reactive Streams specification, for building non-blocking applications on the JVM. Reactor is fully non-blocking and provides efficient demand management. It directly interacts with Java's functional API, CompletableFuture, Stream, and Duration. Reactor offers two reactive and composable APIs, Flux [N] and Mono [0|1], which extensively implement Reactive Extensions. Well-suited for a microservices architecture, Reactor offers backpressure-ready network engines for HTTP (including Websockets), TCP, and UDP. -
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ReplicaDB
ReplicaDB is open source tool for database replication
ReplicaDB is an open-source, multi-platform tool for database replication, enabling the migration and synchronization of data across different relational and NoSQL databases. It is optimized for efficiency and minimal downtime. -
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SchemaCrawler
Free database schema discovery and comprehension tool
SchemaCrawler is a free database schema discovery and comprehension tool. SchemaCrawler has a good mix of useful features for data governance. You can search for database schema objects using regular expressions, and output the schema and data in a readable text format. The output serves for database documentation, and is designed to be diff-ed against other database schemas. SchemaCrawler also generates schema diagrams. You can execute scripts in any standard scripting language against your database. You can find potential schema design issues with lint. SchemaCrawler supports almost any database that has a JDBC driver, but for convenience is bundled with drivers for some commonly used RDBMS systems. SchemaCrawler works with any operating system that supports Java SE 8 or better. SchemaCrawler is also a Java API that makes working with database metadata as easy as working with plain old Java objects.
