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

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  • 1
    Technical analysis library with indicators like ADX, MACD, RSI, Stochastic, TRIX... includes also candlestick pattern recognition. Useful for trading application developpers using either Excel, .NET, Mono, Java, Perl or C/C++.
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    Downloads: 15,535 This Week
    Last Update:
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  • 2
    Arduino

    Arduino

    Open-source electronics platform

    Arduino is an open-source physical computing platform based on a simple I/O board and a development environment that implements the Processing/Wiring language. Arduino can be used to develop stand-alone interactive objects or can be connected to software on your computer (e.g. Flash, Processing and MaxMSP). The boards can be assembled by hand or purchased preassembled. Arduino is a popular tool for IoT product development as well as one of the most successful tools for STEM/STEAM education. Hundreds of thousands of designers, engineers, students, developers and makers around the world are using Arduino to innovate in music, games, toys, smart homes, farming, autonomous vehicles, and more. Arduino is the first widespread Open Source Hardware project and was set up to build a community that could help spread the use of the tool and benefit from contributions from hundreds of people who helped debug the code, write examples, create tutorials, etc.
    Downloads: 125 This Week
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  • 3
    MOA - Massive Online Analysis

    MOA - Massive Online Analysis

    Big Data Stream Analytics Framework.

    A framework for learning from a continuous supply of examples, a data stream. Includes classification, regression, clustering, outlier detection and recommender systems. Related to the WEKA project, also written in Java, while scaling to adaptive large scale machine learning.
    Downloads: 43 This Week
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  • 4
    PLEASE NOTE that we are in the process of moving to GitHub: https://github.com/jasypt/jasypt Jasypt (Java Simplified Encryption) is a java library which allows the developer to add basic encryption capabilities to his/her projects with minimum effort, and without the need of having deep knowledge on how cryptography works. PLEASE NOTE that we are in the process of moving to GitHub: https://github.com/jasypt/jasypt
    Downloads: 14 This Week
    Last Update:
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  • 5
    X's Recommendation Algorithm

    X's Recommendation Algorithm

    Source code for the X Recommendation Algorithm

    The Algorithm is Twitter’s open source release of the core ranking system that powers the platform’s home timeline. It provides transparency into how tweets are selected, prioritized, and surfaced to users, reflecting Twitter’s move toward openness in recommendation algorithms. The repository contains the recommendation pipeline, which incorporates signals such as engagement, relevance, and content features, and demonstrates how they combine to form ranked outputs. Written primarily in Scala, it shows the architecture of large-scale recommendation systems, including candidate sourcing, ranking, and heuristics. While certain components (such as safety layers, spam detection, or private data) are excluded, the release provides valuable insights into the design of real-world machine learning–driven ranking systems. The project is intended as a reference for researchers, developers, and the public to study, experiment with, and better understand the mechanisms behind social media content.
    Downloads: 2 This Week
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  • 6
    JavaBlock
    Free Java Flowchart simulator / interpreter
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    Downloads: 41 This Week
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  • 7
    jFuzzyLogic is a java implementation of a Fuzzy Logic software package. It implements a complete Fuzzy inference system (FIS) as well as Fuzzy Control Logic compliance (FCL) according to IEC 61131-7 (formerly 1131-7).
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    Downloads: 11 This Week
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  • 8
    basE91 is an advanced method for encoding binary data as ASCII characters. It is similar to UUencode or base64, but is more efficient. The overhead produced by basE91 depends on the input data. It amounts at most to 23% and can range down to 14%.
    Downloads: 30 This Week
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  • 9
    AhoCorasickDoubleArrayTrie

    AhoCorasickDoubleArrayTrie

    An extremely fast implementation of Aho Corasick algorithm

    AhoCorasickDoubleArrayTrie is a Java implementation of the Aho–Corasick multi-pattern matching algorithm that is optimized using a Double-Array Trie data structure. It is designed for fast keyword scanning across large texts, where you want to search for many patterns simultaneously and efficiently. The core idea is to build an automaton from a dictionary of patterns, then stream through input text to emit matches with minimal overhead. By using a double-array trie representation, the project emphasizes performance and memory efficiency compared to simpler pointer-heavy trie structures, which can matter a lot for large dictionaries or latency-sensitive services. This makes it a strong fit for tasks like content filtering, entity/term spotting, dictionary-based annotation, or high-throughput log/text processing. In short, it’s a specialized, speed-focused library for industrial-strength multi-keyword matching in Java.
    Downloads: 1 This Week
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  • 10
    leetcode-editor

    leetcode-editor

    Do Leetcode exercises in IDE

    Do Leetcode exercises in IDE, support leetcode.com and leetcode-cn.com, to meet the basic needs of doing exercises.Support theoretically: IntelliJ IDEA PhpStorm WebStorm PyCharm RubyMine AppCode CLion GoLand DataGrip Rider MPS Android Studio. The login accounts of the two websites are not interoperable and the corresponding users need to be configured when switching websites. You can also refresh and load questions if you are not logged in, but you cannot submit it. Input the content and press Enter to search , press again to search for the next one. It can only search under the question bank node. Clean up the files in the configured cache directories. The cache directories of the two websites are different and only the current configured websites are cleaned up. Carefully clean up cases without submitting.
    Downloads: 1 This Week
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  • 11
    The JTS Topology Suite is an API for modelling and manipulating 2-dimensional linear geometry. It provides numerous geometric predicates and functions. JTS conforms to the Simple Features Specification for SQL published by the Open GIS Consortium.
    Downloads: 4 This Week
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  • 12
    CADI is an implementation of the JPIP standard (JPEG2000 Interactive Protocol - Part 9). CADI includes a JPIP server, a JPIP proxy, and a JPIP Client. CADI is designed and programmed with the aim to provide a flexible framework to test and develop ne
    Downloads: 16 This Week
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  • 13
    CloudI: A Cloud at the lowest level
    CloudI is an open-source private cloud computing framework for efficient, secure, and internal data processing. CloudI provides scaling for previously unscalable source code with efficient fault-tolerant execution of ATS, C/C++, Erlang/Elixir, Go, Haskell, Java, JavaScript/node.js, OCaml, Perl, PHP, Python, Ruby, or Rust services. The bare essentials for efficient fault-tolerant processing on a cloud!
    Downloads: 14 This Week
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  • 14
    Java Machine Learning Library is a library of machine learning algorithms and related datasets. Machine learning techniques include: clustering, classification, feature selection, regression, data pre-processing, ensemble learning, voting, ...
    Downloads: 13 This Week
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  • 15
    Jenetics: Java Genetic Algorithm Library
    The source code has been migrated and is now hosted on Github: https://github.com/jenetics/jenetics Jenetics is an advanced Genetic Algorithm, Evolutionary Algorithm and Genetic Programming library, respectively, written in modern day Java. It is designed with a clear separation of the several algorithm concepts, e. g. Gene, Chromosome, Genotype, Phenotype, Population and fitness Function. Jenetics allows you to minimize or maximize the given fitness function without tweaking it. In contrast to other GA implementations, the library uses the concept of an evolution stream (EvolutionStream) for executing the evolution steps. Since the EvolutionStream implements the Java Stream interface, it works smoothly with the rest of the Java Stream API. Other repositories: - https://github.com/jenetics/jenetics Maven: - https://mvnrepository.com/artifact/io.jenetics
    Downloads: 2 This Week
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  • 16
    DJVU++

    DJVU++

    The DjVu complete solution,with OCR Technology(Arabic ,English).

    DjVu++ is a user-friendly program that used to manipulate DjVu file formats such as eBooks with a penalty of editing features. The program introduce a free replacement for the property PDF format with similar resolution and smaller file size DjVu++ also support OCR to handle text in scanned books and images. The program shows good performance for English. In addition to the Arabic language to lead free and commercial software in this area. The main features of DjVu++ program are: o Manipulate DjVu files. o Support smaller size than PDF with the same performance. o DjVu++ supports two languages in the OCR technique (Arabic and English). o Read multiple documents at the same time with the new tabs feature. o DjVu++ supports multiple formats:  Convert PDF document into DjVu format with smaller file size and the same performance.  Convert DjVu into PDF format.  Combine images to a single DjVu document. Perform OCR operations on multiple image formats.
    Downloads: 6 This Week
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  • 17
    TimeFinder automatically optimizes schedules (timetables) for universities and high schools. It makes manual timetabling for the timetabler easier via a Java GUI. Export+import is supported via xml and text formats. http://timefinder.sourceforge.net/
    Downloads: 4 This Week
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  • 18
    McuOnEclipse

    McuOnEclipse

    Releases of McuOnEclipse projects

    Processor Expert components and Eclipse examples and plugins.
    Downloads: 6 This Week
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  • 19
    PortugolViana é uma ferramenta open-source para edição/execução algorítmica. PortugolViana permite a edição de algoritmos em português (do Brasil e de Portugal) e a sua execução e monitorização.
    Downloads: 6 This Week
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  • 20
    Groove
    NOTE: The GROOVE codebase has moved to https://github.com/nl-utwente-groove
    Downloads: 2 This Week
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  • 21
    Java Combinatorial Optimization Platform
    Java Combinatorial Optimization Platform is used to solve combinatorial problems using common interface, providing means to easily add new algorithms and problems and to benchmark them.
    Downloads: 2 This Week
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  • 22
    JoSQL (Java Objects SQL) provides SQL capabilities for querying, ordering and grouping of collections of Java objects (POJOs). It allows a SQL statement to be applied to the collection of objects and the matching set returned, ordered and grouped.
    Downloads: 3 This Week
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  • 23
    Java·Applied·Geodesy·3D

    Java·Applied·Geodesy·3D

    Least-Squares Adjustment Software for Geodetic Sciences

    JAG3D is no longer developed at source-forge, and has moved to GitHub. Please visit https://github.com/applied-geodesy/jag3d or https://software.applied-geodesy.org to get the latest version.
    Downloads: 5 This Week
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  • 24
    Common Java data structure library used by multiple projects. See http://verdantium.blogspot.com/
    Downloads: 4 This Week
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  • 25
    A Java library and set of tools to quickly and easily manipulate graphs (set of nodes and edges) and dynamic graphs. The principal trait of this library is its ability to manage (create, edit, layout, display) continuously evolving graphs. The development of this project now takes place on Github. Visit the official Graphstream website at http://graphstream-project.org
    Downloads: 2 This Week
    Last Update:
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