Actually it was planned that the long-awaited XE version 18c would be available for download in August. Oracle has now decided that the XE version will not be released until October RU4. The reasons for this are some bugs found in last release candidate. I had the opportunity to test this RC and understand that it is better to wait another 3 months in terms of software quality.
As soon as I receive a version which will be released, I will of course blog about my experiences and the effective features and limitations.
More infos in the official post from Gerald Venzl Product Manager Oracle XE