Apparentely this seems a silly question, however at a job interview you might be surprised to hear the question: "How do you find out the JBoss version you are running ?" (Provided that you don't have access to the server logs).
As far as it concerns WildFly, well, it's accessible both from the Web Console and the Command Line Interface. On the Web console, you can find it out at the following link: http://localhost:9990/console/index.html#standalone-server :
When using the Command Line, you can retrieve the exact version through the product-info command:
:product-info() { "outcome" => "success", "result" => [{"summary" => { "host-name" => "localhost", "instance-identifier" => "8f704bd3-9eac-436a-b6d1-56434eab4363", "product-name" => "WildFly Full", "product-version" => "10.0.0.Final", "product-community-identifier" => "Product", "product-home" => "/home/ehsavoie/dev/wildfly/wildfly/dist/target/wildfly-10.0.0.Final", "standalone-or-domain-identifier" => "STANDALONE_SERVER", "host-operating-system" => "Ubuntu 15.04", }
Finally, it's worth mentioning that the standalone script includes also the --version flag which allows (at startup) to check the server version:
$ ./standalone.sh --version ========================================================================= JBoss Bootstrap Environment JBOSS_HOME: /home/francesco/jboss/wildfly-15.0.0.Final JAVA: java JAVA_OPTS: -server -Xms64m -Xmx512m -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=256m -Djava.net.preferIPv4Stack=true -Djboss.modules.system.pkgs=org.jboss.byteman -Djava.awt.headless=true ========================================================================= 17:50:51,084 INFO [org.jboss.modules] (main) JBoss Modules version 1.8.7.Final WildFly Full 15.0.0.Final (WildFly Core 7.0.0.Final) ntinue . . .
Older JBoss versions
If you look at the server logs, every application server release boots with information about the server version:
10:23:56,860 INFO [Server] Release ID: JBoss [Trinity] 4.2.2.GA (build: SVNTag=JBoss_4_2_2_GA date=200710221139)
However interview questions are seldom based on real case examples but more often used to test if you are a smart guy or not. So, in releases 4.X to 6.X you can find it using the jmx-console digging into the jboss.system domain. The following MBean request to find out the JBoss version you are running:
http://localhost:8080/jmx-console/HtmlAdaptor?action=inspectMBean&name=jboss.system%3Atype%3DServer
Which will return a set of Server properties including the release of the application server: