Browse free open source Java Libraries and projects below. Use the toggles on the left to filter open source Java Libraries by OS, license, language, programming language, and project status.

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  • 1
    libjpeg-turbo

    libjpeg-turbo

    SIMD-accelerated libjpeg-compatible JPEG codec library

    libjpeg-turbo is a JPEG image codec that uses SIMD instructions (MMX, SSE2, NEON, AltiVec) to accelerate baseline JPEG compression and decompression on x86, x86-64, ARM, and PowerPC systems. On such systems, libjpeg-turbo is generally 2-6x as fast as libjpeg, all else being equal. On other types of systems, libjpeg-turbo can still outperform libjpeg by a significant amount, by virtue of its highly-optimized Huffman coding routines. In many cases, the performance of libjpeg-turbo rivals that of proprietary high-speed JPEG codecs. libjpeg-turbo implements both the traditional libjpeg API as well as the less powerful but more straightforward TurboJPEG API. libjpeg-turbo also features colorspace extensions that allow it to compress from/decompress to 32-bit and big-endian pixel buffers (RGBX, XBGR, etc.), as well as a full-featured Java interface.
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    Downloads: 42,137 This Week
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  • 2
    Recaf

    Recaf

    The modern Java bytecode editor

    Recaf is an open-source Java bytecode editor that simplifies the process of editing compiled Java applications. To make things easier Recaf abstracts away much of the internal class file format. Difficult tasks such as updating stack-frames are done automatically. Along with additional features to assist in the process of editing classes, Recaf is the most feature-rich free bytecode editor available. While Recaf makes bytecode editing a more simple process it does not mean you should dive head-first into editing compiled Java applications without understanding some basic programming concepts and the Java class file architecture.
    Downloads: 188 This Week
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  • 3
    UCanAccess

    UCanAccess

    A pure Java JDBC driver for Microsoft Access database files

    UCanAccess is a pure Java JDBC Driver implementation which allows Java developers and JDBC client programs to read/write Microsoft Access database (.mdb and .accdb) files. No ODBC needed.
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    Downloads: 712 This Week
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  • 4
    Autopsy

    Autopsy

    Autopsyยฎ is a digital forensics platform and graphical interface

    Autopsyยฎ is a digital forensics platform and graphical interface to The Sleuth Kitยฎ and other digital forensics tools. It can be used by law enforcement, military, and corporate examiners to investigate what happened on a computer. You can even use it to recover photos from your camera's memory card. Autopsy was designed to be intuitive out of the box. Installation is easy and wizards guide you through every step. All results are found in a single tree. See the intuitive page for more details. Autopsy was designed to be an end-to-end platform with modules that come with it out of the box and others that are available from third-parties.
    Downloads: 109 This Week
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  • 5
    EssentialsX

    EssentialsX

    The modern Essentials suite for Spigot and Paper

    EssentialsX is a continuation of the Essentials plugin suite, updated to support modern Minecraft and Spigot versions. It provides countless new features, performance enhancements and fixes that are not available in the original Essentials or Spigot-Essentials. If you're coming from the original Essentials plugin, EssentialsX is a drop-in replacement for Essentials.
    Downloads: 103 This Week
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  • 6
    JFreeChart
    JFreeChart is a free (LGPL) chart library for the Java(tm) platform. It supports bar charts, pie charts, line charts, time series charts, scatter plots, histograms, simple Gantt charts, Pareto charts, bubble plots, dials, thermometers and more. *** JFreeChart has moved to GitHub: https://github.com/jfree/jfreechart ***
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    Downloads: 337 This Week
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  • 7
    ZXing

    ZXing

    Barcode scanning library for Java, Android

    ZXing or โ€œZebra Crossingโ€ is an open source multi-format 1D/2D barcode image processing library thatโ€™s been implemented in Java, and also comes with ports to other languages. It currently supports the following formats: UPC-A and UPC-E EAN-8 and EAN-13 Code 39 Code 93 Code 128 ITF Codabar RSS-14 (all variants) RSS Expanded (most variants) QR Code Data Matrix Aztec ('beta' quality) PDF 417 ('alpha' quality) MaxiCode ZXing is made up of several modules, including a core image decoding library, JavaSE-specific client code, and Android client Barcode Scanner. It is the basis of many other third-party open source projects.
    Downloads: 74 This Week
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  • 8
    JSON-java

    JSON-java

    A reference implementation of a JSON package in Java

    JSON is a light-weight language-independent data interchange format. The JSON-Java package is a reference implementation that demonstrates how to parse JSON documents into Java objects and how to generate new JSON documents from the Java classes.
    Downloads: 56 This Week
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  • 9
    Hacker Scripts

    Hacker Scripts

    Based on a true story

    Hacker Scripts is a cheeky collection of small automation scripts and language ports collected under the tagline โ€œBased on a true story.โ€ The repository gathers playful utilities (originally shell and Ruby scripts) that automate short, real-world tasks โ€” for example, sending a quick โ€œlate at workโ€ text when SSH sessions are active, firing off an automated โ€œIโ€™m sick / working from homeโ€ email on certain mornings, or even talking to a networked coffee machine to start brewing at precisely the right moment. The README explains the origin story and highlights several canonical scripts and provides usage notes such as required environment variables and cron examples for scheduling. Contributors have provided implementations and ports in many languages and folders (shell, Ruby, Python, Node, Perl, PowerShell, Go, Java, etc.), and the project explicitly welcomes pull requests that add additional language implementations.
    Downloads: 46 This Week
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  • 10
    Aliucord

    Aliucord

    A modification for the Discord Android App

    Aliucord is a modification for the Android Discord app.
    Downloads: 44 This Week
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  • 11
    EMV NFC Paycard Enrollment

    EMV NFC Paycard Enrollment

    A Java library used to read and extract data from NFC EMV credit cards

    Java library used to read and extract public data from NFC EMV credit cards.
    Downloads: 35 This Week
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  • 12
    VisualVM

    VisualVM

    VisualVM is an All-in-One Java Troubleshooting Tool

    VisualVM is a visual tool integrating command line JDK tools and lightweight profiling capabilities. Designed for both development and production time use. Use Apache Ant 1.9.9 or above and Oracle JDK 8 to build VisualVM from this repository. VisualVM monitors and troubleshoots applications running on Java 1.4+ from many vendors using various technologies including jvmstat, JMX, Serviceability Agent (SA) and Attach API. VisualVM perfectly fits all the requirements of application developers, system administrators, quality engineers and end users. VisualVM automatically detects and lists locally and remotely running Java applications (jstatd must be running on the remote host). You can also define applications manually by JMX connection. For each process VisualVM shows basic runtime information: PID, main class, arguments passed to java process, JVM version, JDK home, JVM flags and arguments and System properties.
    Downloads: 34 This Week
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  • 13
    LWJGL

    LWJGL

    Java library that enables cross-platform access to popular native APIs

    LWJGL is a Java library that enables cross-platform access to popular native APIs useful in the development of graphics (OpenGL, Vulkan), audio (OpenAL) and parallel computing (OpenCL) applications. This access is direct and high-performance, yet also wrapped in a type-safe and user-friendly layer, appropriate for the Java ecosystem. LWJGL is an enabling technology and provides low-level access. It is not a framework and does not provide higher-level utilities than what the native libraries expose. As such, novice programmers are encouraged to try one of the frameworks or game engines that make use of LWJGL, before working directly with the library.
    Downloads: 30 This Week
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  • 14
    International Components for Unicode

    International Components for Unicode

    The home of the ICU project source code

    ICU is a mature, widely used set of C/C++ and Java libraries providing Unicode and Globalization support for software applications. ICU is widely portable and gives applications the same results on all platforms and between C/C++ and Java software. ICU is released under a nonrestrictive open-source license that is suitable for use with both commercial software and with other open-source or free software. Convert text data to or from Unicode and nearly any other character set or encoding. ICU's conversion tables are based on charset data collected by IBM over the course of many decades and is the most complete available anywhere. Compare strings according to the conventions and standards of a particular language, region or country. ICU's collation is based on the Unicode Collation Algorithm plus locale-specific comparison rules from the Common Locale Data Repository, a comprehensive source for this type of data.
    Downloads: 25 This Week
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  • 15
    AnLinux

    AnLinux

    AnLinux allow you to run Linux on Android without root access

    AnLinux allow you to run Linux on Android without root access. The bash script downloads the image over the internet, then decompresses the image, and then mounts it using PRoot.
    Downloads: 23 This Week
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  • 16
    Apache Log4j

    Apache Log4j

    Apache Log4j 2 is a versatile, feature-rich, efficient logging API

    Apache Log4j is a versatile, industrial-grade Java logging framework composed of an API, its implementation, and components to assist the deployment for various use cases. Log4j is used by 8% of the Maven ecosystem and listed as one of the top 100 critical open source software projects. The project is actively maintained by a team of several volunteers and supported by a big community.
    Downloads: 23 This Week
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  • 17
    iText

    iText

    iText for Java represents the next level of SDKs for developers

    iText for Java represents the next level of SDKs for developers who want to take advantage of the benefits PDF can bring. Equipped with a better document engine, high and low-level programming capabilities and the ability to create, edit, and enhance PDF documents, iText can be a boon to nearly every workflow. iText Suite refers to the complete line of products comprising the open-source iText Core PDF library and its add-ons. The iText Suite is a fully-featured SDK for PDF development that allows you to seamlessly embed extensive PDF functionality into your software or workflows. The iText Suite builds on over a decade of lessons learned from iText 5 (and iTextSharp) development. The latest release of iText, version 8, is a simpler, more performant and extensible library that is ready to handle the increased challenges of today's document workflows, one add-on at a time.
    Downloads: 20 This Week
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  • 18
    tlaplus

    tlaplus

    TLC is an explicit state model checker for specifications in TLA+

    TLC is an explicit state model checker for specifications written in TLA+. The TLA+Toolbox is an IDE for TLA+. TLA+ is a high-level language for modeling programs and systems--especially concurrent and distributed ones. It's based on the idea that the best way to describe things precisely is with simple mathematics. TLA+ and its tools are useful for eliminating fundamental design errors, which are hard to find and expensive to correct in code.
    Downloads: 19 This Week
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  • 19
    A Java JNA wrapper for Tesseract OCR API
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    Downloads: 112 This Week
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  • 20
    JNativeHook

    JNativeHook

    Global keyboard and mouse listeners for Java

    JNativeHook is a library to provide global keyboard and mouse listeners for Java. This will allow you to listen for global shortcuts or mouse motion that would otherwise be impossible using pure Java. To accomplish this task, JNativeHook leverages platform-dependent native code through Java's native interface to create low-level system-wide hooks and deliver those events to your application.
    Downloads: 17 This Week
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  • 21
    ConnectBot

    ConnectBot

    ConnectBot is the first SSH client for Android

    ConnectBot is a secure shell client for the Android platform. Its ultimate goal is to create a secure connection through which you can use a shell on a remote machine and transfer files back and forth to your phone. ConnectBot is a powerful open source SSH (Secure Shell) client. It can handle several simultaneous sessions, create secure connections in tunnel mode and allows Copy/Paste from other applications. This client allows you to connect to SSH (Secure Shell) servers that typically include UNIX-based servers.
    Downloads: 15 This Week
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  • 22
    WebDriverManager

    WebDriverManager

    Automated driver management and helper features for Selenium WebDriver

    WebDriverManager is an open-source Java library that carries out the management (i.e., download, setup, and maintenance) of the drivers required by Selenium WebDriver (e.g., chromedriver, geckodriver, msedgedriver, etc.) in a fully automated manner. In addition, WebDriverManager provides other relevant features, such as the capability to discover browsers installed in the local system, building WebDriver objects (such as ChromeDriver, FirefoxDriver, EdgeDriver, etc.), and running browsers in Docker containers seamlessly. The primary use of WebDriverManager is the automation of driver management. For using this feature, you need to select a given manager in the WebDriverManager API (e.g., chromedriver() for Chrome) and invoke the method setup(). The following example shows the skeleton of a test case using JUnit 5, Selenium WebDriver, and WebDriverManager.
    Downloads: 15 This Week
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  • 23
    HikariCP

    HikariCP

    A solid, high-performance, JDBC connection pool at last

    HikariCP is a high-performance JDBC connection pooling library designed to offer minimal overhead and maximum throughput. It aims for simplicity and stability, concentrating on fast connection acquisition and minimal latency under load. Its internals manage a pool of connections aggressively but smartly, with options such as leak detection, timeout thresholds, and adaptive connection retirement. Because it avoids heavy internal locking, it scales well in high-concurrency environments, making it a popular choice in microservices and high-throughput web backends. Metrics and instrumentation hooks (for example, via Dropwizard or Micrometer) allow runtime visibility into pool usage and health. HikariCPโ€™s focus is on doing the essential work of pooling correctly and efficiently, rather than bundling extraneous features.
    Downloads: 13 This Week
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  • 24
    BIMserver

    BIMserver

    The open source BIMserver platform

    The Building Information Model server (short: BIMserver) enables you to store and manage the information of a construction (or other building related) project. Data is stored in the open data standard IFC. The BIMserver is not a fileserver, but it uses a model-driven architecture approach. This means that IFC data is stored as objects. You could see BIMserver as an IFC database, with special extra features like model checking, versioning, project structures, merging, etc. The main advantage of this approach is the ability to query, merge and filter the BIM model and generate IFC output (i.e. files) on the fly. Thanks to its multi-user support, multiple people can work on their own part of the dataset, while the complete dataset is updated on the fly. Other users can get notifications when the model (or a part of it) is updated.
    Downloads: 12 This Week
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  • 25
    MCProtocolLib

    MCProtocolLib

    A library for communication with a Minecraft client/server

    MCProtocolLib is a simple library for communicating with Minecraft clients and servers. It allows developers to build custom bots, clients, or servers for Minecraft with ease.
    Downloads: 11 This Week
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