Most OpenJDK implementations do not require a license. There are multiple implementations of the Java VM. Java is designed by a collaboration of companies and

Most OpenJDK implementations do not require a license. There are multiple implementations of the Java VM. Java is designed by a collaboration of companies and OpenJDK is the reference implementation. Based on the license of the company, its implementation is free or not. Now, Oracle was the biggest and most well known contributor of OpenJDK for a long time (and probably still is). And Oracle did something unusual, which is that they made their own version no longer free. Which is why you are confused. You can still get Java from Oracle, with Long Term Support, but now it is paid support. The OpenJDK reference implementation is still free, and many companies have made their own tweaks and provide Long Term Support for these versions, mostly because they use tons of Java and/or want others to keep using Java because of its massive ecosystem, for which they can provide consulting/paid support. Note, you can still run these versions commercially, but if you want support you likely have to pay. The Google issue was that before all this OpenJDK stuff, all designing of Java was done by a single company, Sun, which was bought by Oracle. So a single company designed, developed, implemented, maintained, and built up the ecosystem of Java. This includes years of R&D in what keywords to use, and how classes work, basically the rules of the language. Tons of developers got into Java. And they attracted big customers like banks and governments to pay them for this R&D with support and development. Then came Google and they said, we like this language design and ecosystem and developer skills, but we don't want to pay for that support, so thanks for all the hard designing of your language, but we will create our own implementation and pay you nothing. Basically Google didn't want to pay it's share of the Java R&D. Now things get a bit blurry because of Oracle, which bought Sun, and tried to make a lot more money off Java while reducing R&D spending. So Oracle isn't too popular either. Things have improved since Oracle decided that Java isn't something to make a lot of money off, and the whole Google debacle. Now Oracle is mostly stewarding the language and other companies are now also contributing features. The past few years there have been some good and strong updates to Java, making it feel more like a leading language than a trailing language. Basically, get AdoptOpenJDK, latest version if possible, and don't use preview features.