I see here https://jakarta.ee/compatibility/ the list with all compatible application servers for each JEE version. The question is, are they the minimum compatible versions or do I have to use the exact same version as written in there?
For example, one of written compatible application servers for Jakarta EE 8 is Wildfly 18.0.0. Would it still be compatible with the latest Wildfly (25.0.1) as of today?
The question is, are they the minimum compatible versions or do i have to use the exact same version as written in there?
They are minimum compatible versions, but there are also maximum compatible versions existing for older specs, and that isn't told by the page explicitly. For example Wildfly 23+ (current known versions) are Jakarta EE 9 compatible. Wildfly 18 and above but below 23 are Jakarta EE 8/Java EE 8 compatible.
See source about Jakarta EE 9:
No backward compatibility. Jakarta EE 9 is not backward compatible with Jakarta EE 8 or Java EE 8. It's not recommended to mix Jakarta EE 8 artifacts with Jakarta EE 9 and vice versa.
Since Jakarta EE 9 changed namespaces from Java EE 8/Jakarta EE 8, it is not possible to be compatible with both even in theory.
