Awesome Java

A curated list of awesome Java frameworks, libraries and software.

• Awesome Java
  • Ancients
  • Build
  • Bytecode Manipulation
  • Cluster Management
  • Code Analysis
  • Compiler-compiler
  • Configuration
  • Constraint Satisfaction Problem Solver
  • Continuous Integration
  • CSV
  • Data structures
  • Database
  • Date and Time
  • Dependency Injection
  • Development
  • Distributed Applications
  • Distributed Databases
  • Distribution
  • Document Processing
  • Functional Programming
  • Game Development
  • GUI
  • High Performance
  • IDE
  • Imagery
  • JSON
  • JVM and JDK
  • Languages
  • Logging
  • Machine Learning
  • Messaging
  • Miscellaneous
  • Monitoring
  • Native
  • Natural Language Processing
  • Networking
  • ORM
  • PDF
  • Reactive libraries
  • REST Frameworks
  • Science
  • Search
  • Security
  • Serialization
  • Server
  • Template Engine
  • Testing
  • Utility
  • Web Crawling
  • Web Frameworks
• Resources
  • Communities
  • Influential Books
  • Podcasts
  • Twitter
  • Websites
• Contributing

Ancients

In existence since the beginning of time and wich will continue being used long after the hype has waned.

• Apache Ant - Build process management with XML.
• cglib - Bytecode generation library.
• GlassFish - Application server and reference implementation for Java EE sponsored by Oracle.
• Hudson - Continuous integration server still in active development.
• JavaServer Faces - Oracle's open-source implementation of the JSF standard, Mojarra.
• JavaServer Pages - Common templating for websites with custom tag libraries.
• Liquibase - Database-independent library for tracking, managing and applying database schema changes.

Build

Tools which handle the buildcycle and dependencies of an application.

• Apache Maven - Declarative build and dependency management which favors convention over configuration. It might be preferable to Apache Ant which uses a rather procedural approach and can be difficult to maintain.
• Bazel - Build tool from Google that builds code quickly and reliably.
• Gradle - Incremental builds which are programmed via Groovy instead of declaring XML. Works well with Maven's dependency management.

Bytecode Manipulation

Libraries to manipulate bytecode programmatically.

• ASM - All purpose, low level, bytecode manipulation and analysis.
• Byte Buddy - Further simplifies bytecode generation with a fluent API.
• Byteman - Manipulate bytecode at runtime via DSL (rules) mainly for testing/troubleshooting.
• Javassist - Tries to simplify the editing of bytecode.

Cluster Management

Frameworks which can dynamically manage applications inside of a cluster.

• Apache Aurora - Apache Aurora is a Mesos framework for long-running services and cron jobs.
• Singularity - Singularity is a Mesos framework that makes deployment and operations easy. It supports web services, background workers, scheduled jobs, and one-off tasks.

Code Analysis

Tools that provide metrics and quality measurements.

• Checkstyle - Static analysis of coding conventions and standards.
• Error Prone - Catches common programming mistakes as compile-time errors.
• FindBugs - Static analysis of bytecode to find potential bugs.
• jQAssistant - Static code analysis with Neo4J-based query language.
• PMD - Source code analysis for finding bad coding practices.
• SonarQube - Integrates other analysis components via plugins and provides an overview of the metrics over time.

Compiler-compiler

Frameworks that help to create parsers, interpreters or compilers.

• ANTLR - Complex full-featured framework for top-down parsing.
• JavaCC - More specific and slightly easier to learn. Has syntactic lookahead.

Configuration

Libraries that provide external configuration.

• config - Configuration library for JVM languages.
• owner - Reduces boilerplate of properties.

Constraint Satisfaction Problem Solver

Libraries that help on implementing optimization and satisfiability problems.

• Choco - Off-the-shelf constraint satisfaction problem solver, which uses constraint programming techniques.
• JaCoP - Includes an interface for the FlatZinc language, enabling it to execute MiniZinc models.
• OptaPlanner - Business planning and resource scheduling optimization solver.
• Sat4J - State-of-the-art SAT solver for boolean and optimization problems.

Continuous Integration

Tools which support continuously building, testing and releasing applications.

• Bamboo - Atlassian's solution with good integration of their other products. You can either apply for an open-source license or buy it.
• CircleCI - Hosted service with a free trial.
• Codeship - Hosted services with a limited free plan.
• fabric8 - Integration platform for containers.
• Go - ThoughtWork's open-source solution.
• Jenkins - Provides server-based deployment services.
• TeamCity - JetBrain's CI solution with a free version.
• Travis - Hosted service often used for open-source projects.

CSV

Frameworks and libraries that simplify reading/writing CSV data.

• uniVocity-parsers - One of the fastest and most feature-complete CSV. Also comes with parsers for TSV and fixed width records.

Database

Everything which simplifies interactions with the database.

• Apache Phoenix - High performance relational database layer over HBase for low latency applications.
• Crate - Distributed data store that implements data synchronization, sharding, scaling, and replication. In addition, it provides a SQL-based syntax to execute queries across a cluster.
• Flyway - Simple database migration tool.
• H2 - Small SQL Database notable for its in-memory functionality.
• HikariCP - High performance JDBC connection pool.
• JDBI - Convenient abstraction of JDBC.
• jOOQ - Generates typesafe code based on SQL schema.
• MapDB - Embedded database engine that provides concurrent collections backed on disk or in off-heap memory.
• Presto - Distributed SQL query engine for big data.
• Querydsl - Typesafe unified queries.

Data structures

Efficient and specific data structures.

• Apache Parquet - Columnar storage format based on assembly algorithms from the Dremel paper by Google.
• Protobuf - Google's data interchange format.
• SBE - Simple Binary Encoding, one of the fastest message formats around.
• Wire - Clean, lightweight protocol buffers.

Date and Time

Libraries related to handling date and time.

• Joda-Time - De facto standard date/time-library before Java 8.
• Time4J - Advanced date and time library.

Dependency Injection

Libraries that help to realize the Inversion of Control paradigm.

• Apache DeltaSpike - CDI extension framework.
• Dagger2 - Compile-time injection framework without reflection.
• Guice - Lightweight but powerful framework that completes Dagger.
• HK2 - Light-weight and dynamic dependency injection framework.

Development

Augmentation of the development process at a fundamental level.

• ADT4J - JSR-269 code generator for algebraic data types.
• AspectJ - Seamless aspect-oriented programming extension.
• Auto - Collection of source code generators.
• DCEVM - Modification of the JVM that allows unlimited redefinition of loaded classes at runtime.
• HotswapAgent - Unlimited runtime class and resource redefinition.
• Immutables - Scala-like case classes.
• JHipster - Yeoman source code generator to create applications based on Spring Boot and AngularJS.
• JRebel - Commercial software that instantly reloads code and configuration changes without redeploys.
• Lombok - Code-generator which aims to reduce the verbosity.
• Spring Loaded - Class reloading agent.
• vert.x - Polyglot event-driven application framework.

Distributed Applications

Libraries and frameworks for writing distributed and fault-tolerant applications.

• Akka - Toolkit and runtime for building concurrent, distributed, and fault tolerant event-driven applications.
• Apache Storm - Realtime computation system.
• Apache ZooKeeper - Coordination service with distributed configuration, synchronization, and naming registry for large distributed systems.
• Hazelcast - Highly scalable in-memory datagrid.
• Hystrix - Provides latency and fault tolerance.
• JGroups - Toolkit for reliable messaging and creating clusters.
• Orbit - Virtual Actors, adding another level of abstraction to traditional actors.
• Quasar - Lightweight threads and actors for the JVM.

Distributed Databases

Databases in a distributed system that appear to applications as a single data source.

• Apache Cassandra - Column-oriented and providing high availability with no single point of failure.
• Apache HBase - Hadoop database for big data.
• Druid - Real-time and historical OLAP data store that excel at aggregation and approximation queries.
• Infinispan - Highly concurrent key/value datastore used for caching.

Distribution

Tools which handle the distribution of applications in native formats.

• Bintray - Version control for binaries which handles the publishing. Can also be used with Maven or Gradle and has a free plan for open-source software or several business plans.
• Central Repository - Largest binary component repository available as a free service to the open-source community. Default used by Apache Maven and available in all other build tools.
• IzPack - Setup authoring tool for cross-platform deployments.
• JitPack - Easy to use package repository for GitHub. Builds Maven/Gradle projects on demand and publishes ready-to-use packages.
• Launch4j - Wraps JARs in lightweight and native Windows executables.
• Nexus - Binary management with proxy and caching capabilities.
• packr - Packs JARs, assets and the JVM for native distribution on Windows, Linux and Mac OS X.

Document Processing

Libraries that assist with processing office document formats.

• Apache POI - Supports OOXML (XLSX, DOCX, PPTX) as well as OLE2 (XLS, DOC or PPT).
• documents4j - API for document format conversion using third-party converters such as MS Word.
• jOpenDocument - Processes the OpenDocument format.

Functional Programming

Libraries that facilitate functional programming.

• Cyclops - Monad and stream utilities, comprehensions, pattern matching, trampolines and much more.
• Fugue - Functional extensions to Guava.
• Functional Java - Implements numerous basic and advanced programming abstractions that assist composition-oriented development.
• Javaslang - Functional component library that provides persistent data types and functional control structures.
• jOOλ - Extension to Java 8 which aims to fix gaps in lambda, providing numerous missing types and a rich set of sequential Stream API additions.

Game Development

Frameworks that support the development of games.

• jMonkeyEngine - Game engine for modern 3D development.
• libGDX - All-round cross-platform, high-level framework.
• LWJGL - Robust framework that abstracts libraries like OpenGL/CL/AL.

GUI

Libraries to create modern graphical user interfaces.

• JavaFX - The successor of Swing.
• Scene Builder - Visual layout tool for JavaFX applications.

High Performance

Everything about high performance computation, from collections to specific libraries.

• Agrona - Data structures and utility methods that are common in high-performance applications.
• Disruptor - Inter-thread messaging library.
• fastutil - Fast and compact type-specific collections.
• GS Collections - Collection framework inspired by Smalltalk.
• HPPC - Primitive collections.
• Javolution - Library for real-time and embedded systems.
• JCTools - Concurrency tools currently missing from the JDK.
• Koloboke - Hash sets and hash maps.
• Trove - Primitive collections.

IDE

Integrated development environments that try to simplify several aspects of development.

• Eclipse - Established, open-souce project with support for lots of plugins and languages.
• IntelliJ IDEA - Supports a lot of JVM languages and provides good options for Android development. The commercial edition targets the enterprise sector.
• NetBeans - Provides integration for several Java SE and EE features from database access to HTML5.

Imagery

Libraries that assist with the creation, evaluation or manipulation of graphical images.

• Imgscalr - Simple and efficient hardware-accelerated image-scaling library implemented in pure Java 2D.
• Picasso - Image downloading and caching library for Android.
• Thumbnailator - Thumbnailator is a high-quality thumbnail generation library for Java.
• ZXing - Multi-format 1D/2D barcode image processing library.

JSON

Libraries that simplify JSON processing.

• Genson - Powerful and easy to use Java to JSON conversion library.
• Gson - Serializes objects to JSON and vice versa. Good performance with on-the-fly usage.
• Jackson - Similar to GSON but has performance gains if you need to instantiate the library more often.
• LoganSquare - JSON parsing and serializing library based on Jackson's streaming API. Outpeforms GSON & Jackson's library.

JVM and JDK

Current implementations of the JVM/JDK.

• JDK 9 - Early access releases of JDK 9.
• OpenJDK - Open-source implementation.

Languages

Languages other than Java that can be used to write JVM applications.

• Scala - Statically typed programming language that fuses the object - oriented model and functional programming ideas.
• Groovy - Optionally typed and dynamic language, with static-typing and static compilation capabilities. Currently an incubating Apache project
• Clojure - Dynamically typed programming language that can be seen as a modern take on Lisp.
• Ceylon - Statically typed object-oriented language developed by RedHat.
• Kotlin - JetBrain's statically typed programming language for the JVM, Android and the browser.

Logging

Libraries that log the behavior of an application.

• Apache Log4j 2 - Complete rewrite with a powerful plugin and configuration architecture.
• kibana - Analyzes and visualizes log files.
• Logback - Robust logging library with interesting configuration options via Groovy.
• logstash - Tool for managing log files.
• Metrics - Expose metrics via JMX or HTTP and can send them to a database.
• SLF4J - Abstraction layer which is to be used with an implementation.

Machine Learning

Tools that provide specific statistical algorithms which allow learning from data.

• Apache Flink - Fast and reliable large-scale data processing engine.
• Apache Hadoop - Storage and large-scale processing of data-sets on clusters of commodity hardware.
• Apache Mahout - Scalable algorithms focused on collaborative filtering, clustering and classification.
• Apache Spark - Data analytics cluster computing framework.
• DeepDive - Creates structured information from unstructured data and integrates it into an existing database.
• Deeplearning4j - Distributed and multi-threaded deep learning library.
• H2O - Analytics engine for statistics over big data.
• Weka - Collection of algorithms for data mining tasks ranging from pre-processing to visualization.

Messaging

Tools that help to send messages between clients in order to ensure protocol independency.

• Aeron - Efficient reliable unicast and multicast message transport.
• Apache ActiveMQ - Message broker that implements JMS and converts synchronous to asynchronous communication.
• Apache Camel - Glues together different transport APIs via Enterprise Integration Patterns.
• Apache Kafka - High-throughput distributed messaging system.
• Hermes - Fast and reliable message broker built on top of Kafka.
• JBoss HornetQ - Clear, concise, modular and made to be embedded.
• JeroMQ - Implementation of ZeroMQ.
• Smack - Cross-platform XMPP client library.

Miscellaneous

Everything else.

• Design Patterns - Implementation and explanation of the most common design patterns.
• Jimfs - In-memory file system.
• Lanterna - Easy console text GUI library similar to curses.
• LightAdmin - Pluggable CRUD UI library for rapid application development.
• OpenRefine - Tool for working with messy data: cleaning, transforming, extending it with web services and linking it to databases.
• RoboVM - Commercial framework with a free trial to write native iOS apps.

Monitoring

Tools that monitor applications in production.

• AppDynamics - Commercial performance monitor.
• JavaMelody - Performance monitoring and profiling.
• Kamon - Tool for monitoring applications running on the JVM.
• New Relic - Commercial performance monitor.
• SPM - Commercial performance monitor with distributing transaction tracing for JVM apps.
• Takipi - Commercial in-production error monitoring and debugging.

Native

For working with platform-specific native libraries.

• JNA - Work with native libraries without writing JNI. Also provides interfaces to common system libraries.

Natural Language Processing

Libraries that specialize on processing text.

• Apache OpenNLP - Toolkit for common tasks like tokenization.
• CoreNLP - Stanford's CoreNLP provides a set of fundamental tools for tasks like tagging, named entity recognition, sentiment analysis and many more.
• LingPipe - Toolkit for a variety of tasks ranging from POS tagging to sentiment analysis.
• Mallet - Statistical natural language processing, document classification, clustering, topic modeling and more.

Networking

Libraries for network programming.

• Async Http Client - Asynchronous HTTP and WebSocket client library.
• Grizzly - NIO framework. Used as a network layer in Glassfish.
• Netty - Framework for building high performance network applications.
• OkHttp - HTTP+SPDY client.
• Undertow - Web server providing both blocking and non-blocking API’s based on NIO. Used as a network layer in WildFly.

ORM

APIs which handle the persistence of objects.

• Ebean - Provides simple and fast data access.
• EclipseLink - Supports a number of persistence standards: JPA, JAXB, JCA and SDO.
• Hibernate - Robust and widely used with an active community.
• MyBatis - Couples objects with stored procedures or SQL statements.
• OrmLite - Lightweight package avoiding the complexity and overhead of other ORM products.

PDF

Everything that helps with the creation of PDF files.

• Apache FOP - Creates PDF from XSL-FO.
• Apache PDFBox - Toolbox for creating and manipulating PDF.
• DynamicReports - Simplifies JasperReports.
• flyingsaucer - XML/XHTML and CSS 2.1 renderer.
• iText - Creates PDF files programmatically but requires a license for commercial purposes.
• JasperReports - Complex reporting engine.

Performance analysis

Tools for performance analysis, profiling and benchmarking.

• jHiccup - Logs and records platform JVM stalls.
• JMH - Microbenchmarking tool for the JVM.
• JProfiler - Commercial profiler.
• LatencyUtils - Utilities for latency measurement and reporting.
• VisualVM - Visual interface for detailed information about running applications.
• YourKit Java Profiler - Commercial profiler.

Reactive libraries

Libraries for developing reactive applications.

• Reactive Streams - Provide a standard for asynchronous stream processing with non-blocking backpressure.
• Reactor - Library for building reactive fast-data applications.
• RxJava - Library for composing asynchronous and event-based programs using observable sequences from the JVM.

REST Frameworks

Frameworks specifically for creating RESTful services.

• Dropwizard - Opinionated framework for setting up modern web applications with Jetty, Jackson, Jersey and Metrics.
• Feign - HTTP client binder inspired by Retrofit, JAXRS-2.0, and WebSocket.
• Jersey - JAX-RS reference implementation.
• RESTEasy - Fully certified and portable implementation of the JAX-RS specification.
• RestExpress - Thin wrapper on the JBOSS Netty HTTP stack to provide scaling and performance.
• RestX - Framework based on annotation processing and compile-time source generation.
• Retrofit - Type-safe REST client.
• Spark - Sinatra inspired framework.
• Swagger - Swagger is a specification and complete framework implementation for describing, producing, consuming, and visualizing RESTful web services.

Science

Libraries for scientific computing and analysis.

• DataMelt - Environment for scientific computation, data analysis and data visualization.
• JGraphT - Graph library that provides mathematical graph-theory objects and algorithms.
• JScience - Provides a set of classes to work with scientific measurements and units.

Search

Engines which index documents for search and analysis.

• Apache Solr - Enterprise search engine optimized for high volume traffic.
• Elasticsearch - Distributed, multitenant-capable full-text search engine with a RESTful web interface and schema-free JSON documents.

Security

Libraries that handle security, authentication, authorization or session management.

• Apache Shiro - Performs authentication, authorization, cryptography and session management.
• Bouncy Castle - All-purpose cryptographic library. JCA provider, wide range of functions from basic helpers to PGP/SMIME operations.
• Cryptomator - Multiplatform transparent client-side encryption of files in the cloud.
• Keycloak - Integrated SSO and IDM for browser apps and RESTful web services.
• PicketLink - Umbrella project for security and identity management.

Serialization

Libraries that handle serialization with high efficiency.

• FlatBuffers - Memory efficient serialization library that can access serialized data without unpacking and parsing it.
• Kryo - Fast and efficient object graph serialization framework.
• FST - JDK compatible high performance object graph serialization.
• MessagePack - Efficient binary serialization format.

Server

Servers which are specifically used to deploy applications.

• Apache Tomcat - Robust all-round server for Servlet and JSP.
• Apache TomEE - Tomcat plus Java EE.
• Jetty - Lightweight, small server, often embedded in projects.
• WebSphere Liberty - Lightweight, modular server developed by IBM
• WildFly - Formerly known as JBoss and developed by Red Hat with extensive Java EE support.

Template Engine

Tools which substitute expressions in a template.

• Apache Velocity - Templates for HTML pages, emails or source code generation in general.
• FreeMarker - General templating engine without any heavyweight or opinionated dependencies.
• Handlebars.java - Logic-less and semantic Mustache templates.
• Thymeleaf - Aims to be a substitute for JSP and works for XML files in general.

Testing

Tools that test from model to the view.

• Apache JMeter - Functional testing and performance measurements.
• Arquillian - Integration and functional testing platform for Java EE containers.
• AssertJ - Fluent assertions that improve readability.
• Awaitility - DSL for synchronizing asynchronous operations.
• Cucumber - BDD testing framework.
• Gatling - Load testing tool designed for ease of use, maintainability and high performance.
• Hamcrest - Matchers that can be combined to create flexible expressions of intent.
• JMockit - Mocks static, final methods and more.
• JUnit - Common testing framework.
• Mockito - Creation of test double objects in automated unit tests for the purpose of TDD or BDD.
• PowerMock - Enables mocking of static methods, constructors, final classes and methods, private methods and removal of static initializers.
• REST Assured - Java DSL for easy testing for REST/HTTP services.
• Selenide - Concise API around Selenium to write stable and readable UI tests.
• Selenium - Portable software testing framework for web applications.
• Spock - JUnit-compatible framework featuring an expressive Groovy-derived specification language.
• TestNG - Testing framework.
• Truth - Google's assertion and proposition framework.
• Unitils - Modular testing library for unit and integration testing.
• WireMock - Stubbs and mocks web services.

Utility

Libraries which provide general utility functions.

• Apache Commons - Provides different general purpose functions like configuration, validation, collections, file upload or XML processing.
• args4j - Command line arguments parser.
• CRaSH - Provides a CLI for running processes.
• Gephi - Cross-platform for visualizing and manipulating large graph networks.
• Guava - Collections, caching, primitives support, concurrency libraries, common annotations, string processing, I/O, and so forth.
• JADE - Framework and environment for building and to debugging multi-agent systems.
• javatuples - Tuples.
• JCommander - Command line arguments parser.
• Protégé - Provides an ontology editor and a framework to build knowledge-based systems.

Web Crawling

Libraries that analyze the content of websites.

• Apache Nutch - Highly extensible, highly scalable web crawler for production environment.
• Crawler4j - Simple and lightweight web crawler.
• JSoup - Scrapes, parses, manipulates and cleans HTML.

Web Frameworks

Frameworks that handle the communication between the layers of an web application.

• Apache Tapestry - Component-oriented framework for creating dynamic, robust, highly scalable web applications.
• Apache Wicket - Component-based web application framework similar to Tapestry with a stateful GUI.
• Google Web Toolkit - Toolbox which includes a Java-to-JavaScript compiler for client-side code, XML parser, API for RPC, JUnit integration, internationalization support and widgets for the GUI.
• Grails - Groovy framework with the aim to provide a highly productive environment by favoring convention over configuration, no XML and support for mixins.
• Ninja - Full stack web framework.
• Pippo - Small, highly modularized Sinatra-like framework.
• Play - Uses convention over configuration, hot code reloading and display of errors in the browser.
• PrimeFaces - JSF framework which has a free and a commercial version with support. Provides several frontend components.
• Ratpack - Set of libraries that facilitate fast, efficient, evolvable and well tested HTTP applications.
• Spring Boot - Microframework which simplifies the development of new Spring applications.
• Spring - Provides many packages ranging from dependency injection to aspect-oriented programming to security.
• Vaadin - Event-driven framework build on top of GWT. Uses server-side architecture with Ajax on the client-side.

Resources

Communities

Active discussions.

• r/java - Subreddit for the Java community.
• stackoverflow - Question/answer platform.
• vJUG - Virtual Java User Group.

Influential Books

Books that had a high impact and are still worth reading.

• Effective Java (2nd Edition)
• Java 8 in Action
• Java Concurrency in Practice
• Thinking in Java

Podcasts

Something to listen to while programming.

• The Java Council
• The Java Posse - Discontinued as of 02/2015.

Twitter

Active accounts to follow. Descriptions from Twitter.

• Adam Bien - Freelancer: Author, JavaONE Rockstar Speaker, Consultant, Java Champion.
• Aleksey Shipilëv - Performance Geek, Benchmarking Tzar, Concurrency Bug Hunter.
• Antonio Goncalves - Java Champion, JUG Leader, Devoxx France, Java EE 6/7, JCP, Author.
• Arun Gupta - Java Champion, JavaOne Rockstar, UG Leader, Devoxx4Kids-er, Red Hatter.
• Brian Goetz - Java Language Architect at Oracle.
• Bruno Borges - Product Manager/Java Jock at Oracle.
• Ed Burns - Consulting Member of the Technical Staff at Oracle.
• Eugen Paraschiv - Author of the Spring Security Course.
• James Weaver - Java/JavaFX/IoT developer, author and speaker.
• Java EE - Official Java EE Twitter account.
• Java Magazine - Official Java Magazine account.
• Java.net - Official Java.net account.
• Java - Official Java Twitter account.
• Javin Paul - Well-known Java blogger.
• Lukas Eder - Founder and CEO Data Geekery (jOOQ).
• Mario Fusco - RedHatter, JUG coordinator, frequent speaker and author.
• Mark Reinhold - Chief Architect, Java Platform Group, Oracle.
• Markus Eisele - Java EE evangelist, Red Hat.
• Martijn Verburg - London JUG co-leader, speaker, author, Java Champion and much more.
• Martin Thompson - Pasty faced performance gangster.
• OpenJDK - Official OpenJDK account.
• Peter Lawrey - Peter Lawrey, Java performance expert.
• Reza Rahman - Java EE/GlassFish/WebLogic evangelist, author, speaker, open source hacker.
• Roberto Cortez - Java EE/JPA expert, speaker, open source.
• Simon Maple - Java Champion, virtualJUG founder, LJC leader, RebelLabs author.
• Stephen Colebourne - Java Champion, speaker.
• Tim Boudreau - Author and NetBeans guru.
• Trisha Gee - Java Champion and speaker.

Websites

Sites to read.

• Android Arsenal
• Google Java Style
• InfoQ
• Java Code Geeks
• Java, SQL, and jOOQ
• Java.net
• Javalobby
• JavaWorld
• JAXenter
• RebelLabs
• The Java Specialist' Newsletter
• The Takipi Blog
• TheServerSide.com
• Thoughts On Java
• Vanilla Java
• Vlad Mihalcea on Hibernate
• Voxxed

Contributing

Contributions are very welcome!

Please have a look at CONTRIBUTING for guidelines.