How Jboss know where to look for user library

Hi,
I am deploying a web application to jboss using eclipse and ANT, which has some external jar attached with it. My question is ,how jboss knows where are these library(jar) files.

I was thinking that libraries will go to web-inf/lib but it is not so; and moreover my application is running smoothly.

I have also checked server/default/lib and other folders.

Any Idea, how the things are working?

Have a look at:

http://wiki.jboss.org/wiki/Wiki.jsp?page=JBossClassLoadingUseCases

http://wiki.jboss.org/wiki/Wiki.jsp?page=ClassLoadingConfiguration