(Photo: oracle by you are the atman)

Most commercial websites that use JBoss also use Oracle.  To run JBoss with Oracle you simply need to tell JBoss where to find the Oracle JDBC drivers. To do this modify run.bat or run.sh and set the JBOSS_CLASSPATH to include the Oracle JDBC jar file before

set JBOSS_CLASSPATH=C:\oracle\product\10.2.0\db_1\jdbc\lib\ojdbc14.jar

I did this right before run.bat checks to see if JBOSS_CLASSPATH is empty.

rem If JBOSS_CLASSPATH or JAVAC_JAR is empty, don't include it, as this will
rem result in including the local directory in the classpath, which makes
rem error tracking harder.
if not "%JAVAC_JAR%" == "" set RUNJAR=%JAVAC_JAR%;%RUNJAR%
if "%JBOSS_CLASSPATH%" == "" set RUN_CLASSPATH=%RUNJAR%
if "%RUN_CLASSPATH%" == "" set RUN_CLASSPATH=%JBOSS_CLASSPATH%;%RUNJAR%

After doing this you might need to tell your web application how to configure the data sources. I wrote a post about how to configure your data source for ATG web applications.