Wink.com is releasing a module called Dum for dumping data.
It derives from Dumper by Richard W Jones (now Std.dump in Extlib) and
from Size by Jean-Christophe Filliatre.

    http://oss.wink.com/dum/

The main improvement over the original Dumper is that shared values
and therefore cycles are detected and labelled:

# let rec loopy = 1 :: 2 :: loopy in Dum.p loopy;;
- : string = "#0: (1 (2 #0))"

Dum was originally developed to print the maximum out of uncaught
exceptions, since the standard Printexc.to_string does not go arbitrarily
deep and this was occasionally a source of frustration.

Now data such as closure fields and object fields are dumped like regular
data without causing particular problems or worries.

The output is pretty-printed and its size limit is configurable.

Enjoy!

Martin, for Wink.

--
http://wink.com/