https://timurakhmadeev.wordpress.com/2010/02/18/ash-viewer/
http://sourceforge.net/projects/ashv/
If you’re running a version of Oracle older than 10g (where v$active_session_history appeared), or if you’re not using Enterprise Edition, or if you just don’t want to pay for the Diagnostic Pack licence, here are some links relating a free Java program that emulates the “Top Sessions” output of the Enterprise Manager screen:
