Java is used by both the client and the server and the versions in use may differ in some cases.
Client #
The version of Java being used by the client is shown on the Help > About dialog as of Promiso 8.1.0.
Server #
- Navigate to the <Apache Tomcat installation folder>\logs\ folder on the server
- Open a recent catalina.yyyy-mm-dd.log file and look for lines that reference JVM Version, JVM Vendor and Java Home towards the top of the file