Since this is a discussion forum, I dare use it to announce a new release of the best (IMO) Java open source discussion software, JForum. There isn't much new in terms of functionality or bug fixes, but it now runs natively on JakartaEE 10 - meaning you need Tomcat 10.1 or comparable to run it. Previous versions ran fine using the webapps-javaee mechanism of Tomcat, but that's supposed to be something of a temporary hack. And for JForum, it's no longer needed now :-)
You can find a ready-to-run war file at https://sourceforge.net/projects/jforum2/, along with documentation.