Since i-net Clear Reports version 18.1 the AdoptOpenJDK 11, which can be used free of charge, is bundled with the installed report server and installed i-net Designer. Only the remote designer version 18.1 requires an installed Java 8 with Java Web Start.
Since i-net Clear Reports version 19.0 users are no longer required to have Java installed separately anymore because the remote Designer now supports a protocol handler to open a locally installed i-net Designer instead of the JNLP variant. It is only required to install a local i-net Designer which contains the AdoptOpenJDK.