Opening this issue after a bit of email exchange with @headius and @enebo (they have already responded to a some questions via email, but I'll let them provide their own answers here directly to avoid any misunderstanding on my part).

As a JRuby user still relying on OpenJDK 8, it would be great to have a page on the JRuby site stating what are the current possibilities & situation after the Oracle Java SE Support Roadmap update.

This blog post and related content (youtube video give a good background on the topic of JDK licensing & release cadence changes.

If I understand well:

• OpenJDK will get a 6-month release cadence.
• LTS support (= longer than 6-month) for e.g. JDK 11 is only available via an Oracle support contract

This poses a number of questions:

• Will the JRuby project (committers but also community) be able to achieve compatibility with the latest JDK every 6-month, to ensure users are able to use an up-to-date JDK? (even accounting for the fact that the retro-compatibility history would be mostly good usually)
• Or maybe this is going to be too hard, enforcing the need to go LTS (with a support contract)?
• Could Amazon Corretto be officially supported by JRuby, hence allowing free use of OpenJDK 8 (and later other versions) on a number of OS (Amazon Linux 2, Microsoft Windows, macOS first, and Red Hat Enterprise + Ubuntu in Q1 2019), for more than 6 months in a row?
• Do we need more options in the current JDK test matrix to support this?
• Could https://adoptopenjdk.net help hear too?

All in all, anything that will help JRuby users or prospects figure out what they can and cannot do in terms of compatibility & licensing, especially without an Oracle support contract, would probably help a number of people I guess.

Well - that's it to get the ball rolling!