UProf is a toolkit for profiling applications and libraries with an emphasis on domain specific instrumentation. Unlike tools such as OProfile or Sysprof UProf can be used to provide application specific reports making statistics more accesible, and encouraging ongoing tracking of key statistics. Also unlike sysprof the current timing features are non-stochastic and measure real world elapsed time (via the rdtsc instruction for x86 CPUs) This gives us a very high precision counter and measuring real world time has proven to be good way of highlighiting non-CPU bound bottlenecks.