In the summer of 2017, Oracle had begun working with the Eclipse Foundation and the Java Enterprise Edition (Java EE) community to transfer its Java EE code and governance responsibilities to the foundation.

The Eclipse Foundation is using “Eclipse Enterprise for Java” or “EE4J” as the umbrella term for the open source project, but because EE4J covers more than just the Java EE code, there remains a need for a brand name for Java EE.

Oracle not letting go of its intellectual property rights in the name “Java.” The Java EE community had to come up with a name to refer to the open source version of Java EE.

There were a total of 7,000 people who participated in the community poll between Feb 8-23, 2018, and over 64% voted in favour of Jakarta EE.

The github issue here, has more information on the naming guidelines and the selection process.