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.

  • $300 Free Credits to Build on Google Cloud Icon
    $300 Free Credits to Build on Google Cloud

    New customers can spin up VMs, build with AI, and query data at no cost.

    Put your $300 in credit toward real workloads, then keep building with free monthly usage for 20+ products. No commitment and no charge until you upgrade.
    Start Free
  • Custom VMs From 1 to 96 vCPUs With 99.95% Uptime Icon
    Custom VMs From 1 to 96 vCPUs With 99.95% Uptime

    General-purpose, compute-optimized, or GPU/TPU-accelerated. Built to your exact specs.

    Live migration and automatic failover keep workloads online through maintenance. One free e2-micro VM every month.
    Start Free
  • 1
    Artificial neural network with eigenfaces for face recognition
    Downloads: 0 This Week
    Last Update:
    See Project
  • 2

    argparse4j

    Command line argument parser library for Java

    The argparse4j is a command line argument parser library for Java based on Python's argparse.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 3
    bigfish

    bigfish

    Library for crossplattform communication

    bisfish is a crossplattform library that can be used with IPhone, Android and Windows Phone 7 projects. It enables you to easily share data between the three platforms. You run a server (programmed in java) to that all the clients will connect. The clients can choose a session to join with. A session can be password protected. In a session you can send messages (bytes) to all of the members of a session, to a group of members or to a single member (broadcast, multicast and unicast).
    Downloads: 0 This Week
    Last Update:
    See Project
  • 4

    bioluminescence

    A java library for polymorphic genome assembly.

    Bioluminescence is a java library for facilitating de novo genome assembly in the context of reads sampled from a single highly-polymorphic diploid individual. Bioluminescence implements a novel algorithm which uses an artificial neural network to classify contigs in a genome assembly as haplotype-specific or not-haplotype-specific. It then uses this information to partition the original input read set into two subsets, each of which has been enriched for one of the haplotypes. Initial results using this technique have dramatically improved de novo asseblies of such data. The implementation provided here remains partial, and under daily development, and is released as a daily "snapshot" as opposed to a static version.
    Downloads: 0 This Week
    Last Update:
    See Project
  • Ship Agents Faster Icon
    Ship Agents Faster

    Transform your applications and workflows into powerful agentic systems at global scale.

    Gemini Enterprise Agent Platform lets you rapidly build, scale, govern and optimize production-ready agents grounded in your organization's data. The platform enables developers to build custom or pre-built agents for virtually any use case. New customers get $300 in free credits.
    Start Free
  • 5

    biweekly

    An iCalendar library written in Java.

    biweekly HAS MOVED TO GITHUB! Watch me, star me, fork me! https://github.com/mangstadt/biweekly biweekly is an iCalendar library written in Java (requires Java 1.5 or above). The project aims to provide a well documented, easy to use API for reading and writing iCalendar and vCalendar data.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 6
    booksource

    booksource

    Source code for the entire book "First Line of Code, 2nd Edition"

    booksource is a collection of Android source-code projects accompanying the second edition of the programming book The First Line of Code. The repository organizes examples by chapter so readers can study working implementations alongside the material. It starts with introductory projects such as Hello World and progresses into broader Android development concepts. Included examples demonstrate activities, lifecycle behavior, layouts, widgets, custom views, ListView, and RecyclerView. Other projects explore fragments, broadcasts, location services, Material Design, and a complete weather application. It serves as a practical reference for learners who want executable examples of concepts discussed throughout the book.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 7

    bornlib

    Set of Java classes

    git server on https://github.com/borneq/bornlib
    Downloads: 0 This Week
    Last Update:
    See Project
  • 8
    Canvas Android buttonImage
    Downloads: 0 This Week
    Last Update:
    See Project
  • 9
    A Java-based toolkit for integration with the Bazaar (bzr) Distributed Version Control System.
    Downloads: 0 This Week
    Last Update:
    See Project
  • Already Paying for an RMM? Get 50% Off Splashtop AEM Icon
    Already Paying for an RMM? Get 50% Off Splashtop AEM

    Switch to Splashtop AEM and save up to 50% in your first year

    Automated OS and third-party patching for Windows and macOS, CVE prioritization with AI patch summaries, and built-in remote control that also supports Linux. Qualifying organizations switching from another RMM get up to 50% off year one.
    Get Started
  • 10

    cairo4j

    Java bindings to cairo

    These are the Java bindings to cairo C graphics library. Main features: - Handcrafted OO bindings updated to version 2.12. JNI code is automatically generated, thanks to Hawtjni library; - Supported on Windows, Linux and Mac; - Draw directly to an AWT Canvas through JAWT; Missing features: - User fonts and raster source patterns are not implemented yet.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 11
    cartdroonize

    cartdroonize

    A free open source lib to cartoonize pics on Android

    A free open source lib to cartoonize pics on Android.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 12
    A project developed by some students from University of Milano Bicocca. It concerns creation of an interface in order to manage WSDLs describing abstract and concrete Web Services.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 13
    An event driven software system for easy and efficient streaming of structured data. Instead of creating temporary objects and holding them in lists for passing around, chain$tar streams data directly to a sequence of chained methods.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 14

    chalkbox

    Java project for using ANSI colors when writing some text

    Trying to tackle the domain from http://en.wikipedia.org/wiki/ANSI_escape_code
    Downloads: 0 This Week
    Last Update:
    See Project
  • 15

    ckeditor.filebrowser

    CKEditor taglib + File Browser

    This is the ported version of the very good grails' plugin, ckeditor. This jsp taglib is very easy to use and the distribution package is in web archive (war) format. You can just drop the war file in the servlet container then test drive from their. For tutorial, please visit the project website.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 16

    clam4j

    A java wrapper for clamd

    Clam4j is designed to be a java wrapper around ClamAV. Clam4j allows you to scan for viruses in java programs by providing a simple java interface which sends the data to clamd for scanning. The results of the scan are returned to the caller via a response object.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 17
    cloud-file-system-sdk

    cloud-file-system-sdk

    CloudFile File System SDK

    EaseFilter Cloud File System is a Windows virtual file system which was developed with the file system filter driver. The Cloud File System integrates the cloud storage into the on-premise storage, it lets on-premise application access the cloud files transparently, just as they would access on-premise regular files. With the Cloud File SDK, the developers can implement the cloud disaster recovery (Cloud DR) solution, seamlessly integrate your existing applications to the cloud environment without affecting the original data and programs, without any modification of your existing applications. It can help the small to medium size companies to implement the Cloud DR with the lowest cost and minimal disruption to normal operation.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 18

    cmd-config

    Command Line Argument Parsing Library

    CmdConfig aims to provide lightweight command line argument parsing for Java programs, beginning with single-character option parsing and adding more advanced features in the future.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 19

    cognity

    A neural network library for Java.

    Cognity is an object-oriented neural network library for Java. It's goal is to provide easy-to-use, high level architecture for neural network computations along with reasonable performance.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 20
    com-hfg

    com-hfg

    java library for XML, HTML, or SVG generation + bioinformatics classes

    The com.hfg (hairyfatguy.com) library is a collection of utility classes that make it easy to construct XML, HTML, XHTML, or SVG in an object-oriented way from within your Java application or webapp. It also contains other IO utilities and bioinformatics classes for phylogenetic trees, taxonomy, and multi-chain proteins. Requires JDK1.8.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 21
    comby

    comby

    A code rewrite tool for structural search and replace that supports

    Comby is a tool for searching and changing code structure. Use lightweight templates to easily search and change code, HTML, or JSON. Comby is designed to work on any language or data format. Perform richer search and replace because Comby understands the syntax of code blocks, strings, and comments for your language. Comby is ideal for touching up pieces of code. Use it to translate code like this Python 2 to 3 fixer on the right to replace deprecated methods. Easily write one-off refactors or a collection of quick fixes customized to your project. Comby makes finding and changing code easier than regex alone allows and avoids pitfalls like escaping parentheses, quotes, or multiline changes.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 22

    commonlib-java

    common java utility library

    useful library for repetitive java stuff
    Downloads: 0 This Week
    Last Update:
    See Project
  • 23

    compactbeans

    Implementation of java.beans.* for JavaSE compact profile 1

    This is a separated-out implementation of the java.beans.Introspector and associated Descriptor classes, targeted at Java 1.8SE Compact Profile 1. The code is based on the openjdk source bundles. The aim is for API compatibility as much as possible. In the simplest case, a package import rename is all that is required. The source code can be found on GitHub at https://github.com/run2000/compactbeans The javadocs can be found at http://compactbeans.sourceforge.net/docs/1.1/api/ The license is the same as for OpenJDK itself. That is, GPL version 2 only, with the "Classpath" exception as described in the LICENSE file.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 24
    compileflow

    compileflow

    Core business process engine of Alibaba Halo platform

    Compileflow is a very lightweight, high-performance, integrable and extensible process engine. The Compileflow process engine is an important part of Taobao Business Process Management(TBBPM), which is dedicated to optimizating operations at Alibaba’s Taobao Marketplace. Specifically, Compileflow is designed to focus on pure memory execution and stateless process engines by converting process files to generate, compile and execute java code. Currently, compileflow powers multiple core systems such as Alibaba's e-commerce stores and transactions. Compileflow allows developers to design their own business processes through the process editor, which will visualize complex business logic, and build a bridge between designers and development engineers.
    Downloads: 0 This Week
    Last Update:
    See Project
  • 25
    Copperhead is a small and simple library providing a Swing user interface that allows one to automatically generate PDF documents from annotated objects using the iText PDF library. Copperhead is developed under GPLv3. Please download Copperhead 0.1b for iText 2 and 0.2b for iText5. Read more on http://byteality.ch/blog. Enjoy!
    Downloads: 0 This Week
    Last Update:
    See Project