MyOra 2.0.0 is completely free software (alternative to commercial products).
This free tool has many useful features for Oracle DBAs and developers.
* Monitor database performance in Real-time using graphs
* Oracle Database Activity display using interactive graphs
* Top 5 SQL display (Explain plan and SQL details)
* Top 5 Resource display (Sessions statistics)
* Run SQL queries and Monitor database performance at the same time
* Open multiple SQL Editors, Schema Explorers, Session Manager... etc..