Ocamlviz gives the ability to instrument an existing code, in real time, with lightweight monitoring annotations. Ocamlviz can also be used as a debugging tool.

Here are a few possibilities provided by Ocamlviz: * observe details about the garbage collector * observe how many times the program goes through a point * make a set of values (any) and count its cardinal number and its size in the heap * observe how much time passed between two points of the program * observe the value of integers, floating-point numbers, booleans and strings * observe details about hash tables, like the number of empty buckets, or the filling rate * etc

This package provides an ASCII client. The monitoring is displayed in a file.