Welcome to these parts. I haven't used Jetty before, but installing it and getting a demo web app to run was simple, so I'll try and see what's involved in getting JForum to run on it.
For example, the MySQL program I installed works fine. But is there some aspect that has to be specifically configured to work with JForum prior to installation?
No, the required information will be asked of you during installation.
"The next step you should do is register the JForum application within your Servlet Container, like Tomcat." I do not see any mention in Jetty about a registration process.
"Registration" is a rather fancy word for this - Jetty seems configured by default to start all war files it finds in the webapps directory; there is no need to tell it about additional web apps if that's where you intend to keep it.
2019-07-23 16:07:24.378:INFO:oejw.StandardDescriptorProcessor:main: NO JSP Support for /jforum-2.6.0, did not find org.eclipse.jetty.jsp.JettyJspServlet
This isn't good - JForum needs JSP, and it should be enabled by default. Check the start.ini file for "--module=jsp". Are you starting Jetty as described in
https://www.eclipse.org/jetty/documentation/9.4.19.v20190610/quickstart-running-jetty.html, using the demo base?
java.lang.Exception: template not found: "C:\Users\Genie\jetty\base\webapps\WEB-INF\log4j_template.xml"
java.io.FileNotFoundException: C:\Users\Genie\jetty\base\webapps\WEB-INF\config\SystemGlobals.properties
That's odd, it should be looking in C:\Users\Genie\jetty\base\webapps\jforum-2.6.0\WEB-INF instead. I'm running into the very same problem (using Java 8), so apparently Jetty works differently than Tomcat. (As an aside, I note that Jetty doesn't create an exploded directory from the war file in the way Tomcat does - I'm fairly certain that will be a problem later on, as JForum expects to be able to write into that directory.) But even unpacking the war file manually and running the web app that way results in this error.
Note that jforum is "not available". Clicking on the link elicits the message "Error 503 Service Unavailable".
Given the error messages, that's not surprising. SystemGlobals.properties is positively required.
I noticed under "System Requirements" that only Apache Tomcat is mentioned as a server. Previously Jetty was also supported, was it not? Is it no longer supported?
The requirement is a Servlet 3.1 container (which Jetty is). Only Tomcat is listed under "Tested" because that's what we use to test JForum. We haven't done anything to make it incompatible with other servlet containers, though, but there may be snags.
The end goal is to provide a new forum for java-gaming.org. As a coder I'm a bit stronger on initiative than skill, and am attempting to put forth JForum as a candidate for consideration. We are currently using SMF.
Cool. I remember perusing those forums WAY back when when I was learning JOGL. Hopefully we can persuade you to choose JForum. In my obviously biased opinion JForum is the best Java open source forum web app.
I'll update this topic with what I find.