What is OpenJDK
May 28, 2020

What is OpenJDK?

Development

OpenJDK is consistently rising in popularity. In this blog we break down, what is OpenJDK? Learn the history of Java, OpenJDK in relation to Oracle JDK, and much more. 

History of Java

Java became wildly popular across enterprises, ISVs, and open source communities like, and as of 2020 is listed as the third most popular programming language in the world, behind Javascript and Python, according to GitHub’s State of the Octoverse report (Language Popularity).

In 2006, Sun Microsystems made the decision to open source Java, and in November of 2006 the majority of the source code for Java was released under the GPL.  This initial release included the Java Virtual Machine (Hotspot) as well as the ‘javac’ Java compiler.  Combined, these components would allow Java developers to both write and run code against a completely free and open source Java platform.

The remainder of the Java Development Kit would follow and by 2007, all but only a few shreds of proprietary code would be released to the community.  By 2010, any of these still proprietary parts of the original code would be replaced by the OpenJDK community with free software.  

What Is OpenJDK?

Java OpenJDK is the community upstream project that represents the current origin point of the Java Runtime Edition and the Java Development Kit. The OpenJDK source code is the basis for these products. The Java language itself is a general-purpose, cross-platform language which was developed by James Gosling at Sun Microsystems in the mid-90s. 

Java solved a number of textbook software development problems at the time, including portability with its write-once, run-anywhere (WORA) approach, simplified memory management, and full abstraction from the operating system.

Today in 2020, the OpenJDK source code is still the base code upon which all other distributions of Java, including the Oracle JDK, are built:
 

OpenJDK Source

 

OpenJDK Feature-Compatible with Oracle

This means that built distributions of OpenJDK are feature-compatible with the Oracle JVM, and that using OpenJDK looks and feels very much like using Oracle JDK, or other builds of OpenJDK that you may be familiar with. Unlike Oracle JDK, even OpenJDK 8 doesn’t come with license obligations.

When you install or run Java OpenJDK in your environment, your experience as both user and developer will not deviate from what you are used to:
 

OpenJDK Environment

OpenJDK 8

Oracle JDK Environment

Java OpenJDK

OpenJDK itself can be acquired in a number of ways, but for modern environments is arguably more accessible than versions of Java which must be downloaded and manually installed. This shouldn’t be surprising – since the code is GPL licensed, it is freely redistributable, so you don’t need to worry about logging into a website or signing into your account to acquire the software.
 
For instance, OpenJDK can be installed into most mainstream Linux environments using a native package manager:

What is OpenJDK

The Best Free Java

In the end, OpenJDK can be thought of as “free” Java.  It is free in the sense that there is no cost associated with it, and free in the sense that you can acquire it easily and redistribute it without worrying about license obligations. 

OpenJDK is by definition more than that, OpenJDK *is* Java, in that the OpenJDK source forms the basis from which all other version of Java is created and, by extension, the use of OpenJDK brings developers closer to the epicenter of Java development.

Get Started with OpenJDK

Are you looking for Enterprise Architects with Java expertise? 

The team at OpenLogic consists of passionate, experienced Enterprise Architects who provide end-to-end services to organizations so they can confidently gain the freedom and savings that come with using open source software. Learn more about open source Java services and support.

With OpenLogic, you can trust you'll be working with an experienced architect with a wealth of experience solving complex challenges in Java environments. The OpenLogic free trial allows you to get real, consultative support from one of our Enterprise Architects, helping you solve real-world challenges with open source.
 

TRY OPENJDK SUPPORT