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: 36,362 This Week
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  • 2
    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 “Based on a true story.” The repository gathers playful utilities (originally shell and Ruby scripts) that automate short, real-world tasks — for example, sending a quick “late at work” text when SSH sessions are active, firing off an automated “I’m sick / working from home” 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: 312 This Week
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  • 3
    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: 228 This Week
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  • 4
    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: 414 This Week
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    Autopsy

    Autopsy

    Autopsy® is a digital forensics platform and graphical interface

    Autopsy® is a digital forensics platform and graphical interface to The Sleuth Kit® 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: 74 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: 222 This Week
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  • 7
    Sesame

    Sesame

    Java RDF Framework

    This project is no longer actively maintained. It is succeeded by the Eclipse RDF4J project, which can be found at GitHub and at http://www.rdf4j.org/. Sesame is a de-facto standard framework for processing RDF data. This includes parsing, scalable storage, reasoning and full SPARQL 1.1 query/update support. Sesame offers a fully modular toolkit and an easy-to-use Java API that can be connected to all leading RDF storage solutions.
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    Downloads: 194 This Week
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  • 8
    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: 39 This Week
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  • 9
    ZXing

    ZXing

    Barcode scanning library for Java, Android

    ZXing or “Zebra Crossing” is an open source multi-format 1D/2D barcode image processing library that’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: 35 This Week
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  • 10
    Gson

    Gson

    A Java serialization/deserialization library to convert Java Objects

    Gson is a Java library developed by Google that allows conversion between Java objects and JSON. It enables serialization and deserialization of Java classes to and from JSON format, handling complex and generic types, nulls, custom naming policies, and more. Gson is lightweight, easy to use, and does not require annotation-based configuration, making it a popular choice for JSON processing in Java applications.
    Downloads: 25 This Week
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  • 11
    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: 23 This Week
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  • 12
    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: 22 This Week
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  • 13
    OpenAPI Generator

    OpenAPI Generator

    OpenAPI Generator allows generation of API client libraries

    With 50+ client generators, you can easily generate code to interact with any server which exposes an OpenAPI document. Maintainers of APIs may also automatically generate and distribute clients as part of official SDKs. Each client supports different options and features, but all templates can be replaced with your own Mustache-based templates. Getting started with server development can be tough, especially if you're evaluating technologies. We can reduce the burden when you bring your own OpenAPI document. Some generators support Inversion of Control, allowing you to iterate on design via your OpenAPI document without worrying about blowing away your entire domain layer when you regenerate code. Ever wanted to iteratively design a MySQL database, but writing table declarations was too tedious? OpenAPI documents allow you to convert the metadata about your API into some other format.
    Downloads: 20 This Week
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  • 14
    PSI Probe

    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.
    Downloads: 20 This Week
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  • 15
    Monero Java Library

    Monero Java Library

    Java library for using Monero

    A Java library for Monero transactions, enabling integration of Monero functions in Java applications.
    Downloads: 19 This Week
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  • 16
    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: 19 This Week
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  • 17
    Hadoop-BAM is a Java library for the manipulation of files in common bioinformatics formats using the Hadoop MapReduce framework with the Picard SAM JDK, and command line tools similar to SAMtools. The file formats currently supported are BAM, SAM, FASTQ, FASTA, QSEQ, BCF, and VCF. For a longer high-level description of Hadoop-BAM, refer to the article "Hadoop-BAM: directly manipulating next generation sequencing data in the cloud" in Bioinformatics Volume 28 Issue 6 pp. 876-877, available online at: http://dx.doi.org/10.1093/bioinformatics/bts054 Note that the library part of Hadoop-BAM is mainly for developers with experience in using Hadoop. The command line tools of Hadoop-BAM should be understandable to all users, but they are limited in scope. See the SeqPig project for a higher-level interface to the file formats supported by Hadoop-BAM: http://seqpig.sourceforge.net See Seal for Hadoop-based read alignment tools, Seal: http://biodoop-seal.sourceforge.net
    Downloads: 177 This Week
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  • 18
    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: 17 This Week
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  • 19
    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: 16 This Week
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  • 20
    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: 15 This Week
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  • 21
    jclasslib bytecode editor

    jclasslib bytecode editor

    Visualizes all aspects of compiled Java class files

    jclasslib bytecode editor is a tool that visualizes all aspects of compiled Java class files and the contained bytecode. Many aspects of class files can be edited in the UI. In addition, it contains a library that enables developers to read and write Java class files and bytecode. All constant pool entries can be edited. Referenced constant pool entries can directly be edited from the context menu that is shown by the "Edit" button of attributes and constant pool entries. Bytecode instructions can be edited from the context menu.
    Downloads: 15 This Week
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  • 22
    Spoon

    Spoon

    Metaprogramming library to analyze and transform Java source code

    Spoon is an open-source library to analyze, rewrite, transform, transpile Java source code. It parses source files to build a well-designed AST with powerful analysis and transformation API. It supports modern Java versions up to Java 20. Spoon is an official Inria open-source project, and member of the OW2 open-source consortium.
    Downloads: 13 This Week
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  • 23
    Jackcess
    A pure Java library for reading from and writing to MS Access databases.
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    Downloads: 61 This Week
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  • 24
    Aliucord

    Aliucord

    A modification for the Discord Android App

    Aliucord is a modification for the Android Discord app.
    Downloads: 12 This Week
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  • 25
    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: 10 This Week
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