The Devel::StackTrace module contains two classes, Devel::StackTrace and
Devel::StackTraceFrame. The goal of this object is to encapsulate the
information that can found through using the caller() function, as well as
providing a simple interface to this data. 

The Devel::StackTrace object contains a set of Devel::StackTraceFrame objects,
one for each level of the stack. The frames contain all the data available
from caller() as of Perl 5.00503. There are changes in Perl 5.6.0 that have
yet to be incorporated.