Oracle Application Server version number

How to determine the exact version number of the Oracle Application Server (OAS).

On the Application Server you can find a file named ias.properties in the folder ORACLE_HOME/config. In this file there in an entry (Version) containing the version number of the Application Server.  This file is usually updated even if the application server has been patched. I patched an installation of an Oracle Forms/Reports server and after installing patchset the version number is 10.1.2.2.0 instead of 10.1.2.0.2