oracle-jdk-vs-openjdk

In this article, we’ll explore the differences between Oracle Java Development Kit and OpenJDK. We’ll first take a quick look at each of them and then make a comparison. After that, we’ll see a list of other JDK implementations.

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JDK (Java Development Kit) is a software development environment used in Java platform programming. It contains a complete Java Runtime Environment, a so-called private runtime. The name came from the fact that it contains more tools than the standalone JRE as well as the other components needed for developing Java applications.

Oracle strongly recommends using the term JDK to refer to the Java SE (Standard Edition) Development Kit (there are also Enterprise Edition and Micro Edition platforms).

Let’s take a look at the Java SE history:

Note: the versions in italics are no longer supported.

We can see that the major releases of Java SE came approximately every two years until Java SE 7. It took five years to move from Java SE 6, and another three to reach Java SE 8 afterward.

Since Java SE 10, we can expect new releases every six months. However, not all releases will be the Long-Term-Support (LTS) releases. As a result of Oracle’s release plan, the LTS product releases will happen only every three years.

Java SE 11 is the latest LTS version, and Java SE 8 will be receiving free public updates until December 2020 for non-commercial usage.

This development kit got its current name after Oracle bought Sun Microsystems in 2010. Before that, the name was SUN JDK, and it was the official implementation of the Java programming language.

OpenJDK is a free and open-source implementation of the Java SE Platform Edition. It was initially released in 2007 as the result of the development that Sun Microsystems started in 2006.

Certainly, we should emphasize that the OpenJDK is an official reference implementation of a Java Standard Edition since version SE 7.

Initially, it was based only on the JDK 7. But, since Java 10, the open-source reference implementation of the Java SE platform is the responsibility of the JDK Project. And, just like for the Oracle, the JDK Project will also deliver new feature releases every six months.

We should note that before this long-running project, there were JDK Release Projects that released one feature and then got discontinued.

Let’s now check out the OpenJDK versions:

In this section, we’ll focus on the key differences between Oracle JDK and OpenJDK.

As we can see in Oracle’s blog post, there are some important changes starting with Java 11.

First of all, Oracle will change its historical “https://www.oracle.com/technetwork/java/javase/terms/license/index.html[BCL]” license with a combination of an open source GNU General Public License v2, with the Classpath Exception (GPLv2+CPE) and commercial license when using the Oracle JDK as part of an Oracle product or service, or when open source software is not welcome.

Each license will have different builds, but those will be functionally identical with only some cosmetic and packaging differences.

Also, traditionally “commercial features” such as Flight Recorder, Java Mission Control, and Application Class-Data Sharing, as well as the Z Garbage Collector, are now available in OpenJDK. Therefore, Oracle JDK and OpenJDK builds are essentially identical from Java 11 onward.

Let’s check out the main differences:

Let’s now take a quick look at other active Java Development Kit implementations.

In this article, we focused on the two most popular Java Development Kits today.

We first described each of them and then emphasized the most notable differences between those. Then, we paid special attention to the changes and differences since Java 11. Finally, we listed other active implementations that are available today.