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

NYTProf is effectively two profilers in one: a statement profiler,
and a subroutine profiler.
