gperftools, originally Google Performance Tools, is a collection of a
high-performance multi-threaded malloc() implementation, plus some
pretty nifty performance analysis tools. gperftools works particularly
well with threads and STL. Also: thread-friendly heap-checker,
heap-profiler, and cpu-profiler.

gperftools was original home for pprof program. But do note that
original pprof (which is still included with gperftools) is now
deprecated.
