When I first set up JForum 2.1.8 I found it quite easy - create the DB, install the web app, run the installer portion of the web app. That was about it. Haven't used any other Java-based forum software, so I can't compare it to anything.
JavaRanch is likely the largest JForum installation in existence (it was a couple of years ago), so our moderators are quite knowledgable about it :-)
Freemarker template language – While this serves the same purpose as a JSP (view) it uses a separate language that forces the Java code to stay out of the view. If we were writing software from scratch we probably would have used JSPs/EL since we had to go and learn Freemarker to use it.
I'm not extatic about Freemarker myself, but I suppose it worth putting up with it for a free forum in Java
Joined: Nov 29, 2009
Only problem I had was having to edit the jforum\WEB-INF\config\database\mysql\mysql_db_struct.sql file with TYPE to ENGINE.