Amazon Corretto is a production-ready distribution of OpenJDK, while the preview release version, Corretto 8 corresponds to Java 8, which installation binaries are currently available for Linux, macOS, and Windows.
Corretto is designed as a drop-in replacement for all Java SE distributions, except in cases where a user is using features not included in OpenJDK, (for instance, Java Flight Recorder) or workloads running on non-HotSpot JVMs.
The open source Corretto distribution of OpenJDK is currently in beta, and preview builds can be downloaded from aws.amazon.com/corretto, with long-term support promise by Amazon, and quarterly updates including bug fixes and security patches.
Amazon will provide security updates at no cost until 2023, and up to Corretto 11. It will include targeted backports from newer releases, as well as newly-developed enhancements from the OpenJDK community.
And the process will involve testing on thousands of Amazon Web services, which will ensure that fixes are released within days of solving the issues.
While Oracle's changes in Java support, the removal of the free long term support (LTS) for Java, have got Amazon customers worried as they'd have to pay for LTS version in order to run workloads.
Amazon has re-affirmed long term support for Java in Amazon Linux, and perhaps this will be followed up with the beta release of Amazon Corretto.