I have not used Toad before but I have heard that it is a very excellent tool for Oracle DBAs for administrating databases. Previously, we were using Oracle 10g grid control. Ever since we have moved to Windows 7, I could no longer get it working on my laptop. I needed an Opensource tool that is similar to Toad or Grid Control.
From TOra Website
TOra is an open-source multi-platform database management GUI that supports accessing most of the common database platforms in use, including Oracle, MySQL, and Postgres, as well as limited support for any target that can be accessed through Qt’s ODBC support. TOra has been built for various Linux distributions, Mac OS X, MS Windows, and UNIX platforms.
In addition to regular query and data browsing functionality, it includes several additional tools useful for database administrators and developers – which aims to help the DBA or developer of database application. Features PL/SQLdebugger, SQL worksheet with syntax highlighting, DB browser and a comprehensive set of DBA tools.
There you go!