Devel::NYTProf is a powerful feature-rich perl source code profiler.

 * Performs per-line statement profiling for fine detail
 * Performs per-subroutine statement profiling for overview
 * Performs per-block statement profiling (the first profiler to do so)
 * Accounts correctly for time spent after calls return
 * Performs inclusive and exclusive timing of subroutines
 * Subroutine times are per calling location (a powerful feature)
 * Can profile compile-time activity, just run-time, or just END time
 * Uses novel techniques for efficient profiling
 * Sub-microsecond (100ns) resolution on systems with clock_gettime()
 * Very fast - the fastest statement and subroutine profilers for perl
 * Handles applications that fork, with no performance cost
 * Immune from noise caused by profiling overheads and I/O
 * Program being profiled can stop/start the profiler
 * Generates richly annotated and cross-linked html reports
 * Trivial to use with mod_perl - add one line to httpd.conf
 * Includes an extensive test suite
 * Tested on very large codebases

WWW: http://search.cpan.org/dist/Devel-NYTProf/