Amazon Corretto

Amazon Corretto is a production-ready distribution of OpenJDK from AWS, provided at no cost with long-term support, multi-platform builds and security and performance patches, available for use on AWS and anywhere else.

Running Java at Amazon's own scale is the credential that matters here, because Corretto is the build AWS uses internally rather than a product it created to sell, which means the patches and performance work are driven by problems Amazon actually hit in production rather than by a roadmap.

Explicitly permitting use outside AWS is a deliberate and important choice, since a free JDK usable only on one cloud would be a lock-in mechanism, and an organisation running some workloads on AWS and others on premises can standardise on one runtime everywhere without a licensing conversation.

Long-term support at no cost is the part that displaced paid alternatives for many teams, because the commercial pressure in this market has always come from support windows rather than the runtime itself, and an organisation that cannot upgrade Java across hundreds of applications quickly is exactly who ends up paying. Corretto covers multiple platforms including Linux, Windows and macOS, ships as container images, and integrates with AWS services such as Lambda where the runtime is a configuration choice rather than an installation. It builds from the same OpenJDK source as every other distribution and is TCK-verified, so moving to it is a packaging change rather than a migration. Corretto is free with no licence fee.