I'm using the readline for toplevel from programmer-monk for a while  
now:

http://pmonk.net/svn/ocaml-misc/readline

I can use the up-down arrows easily which is usually enough.  Still  
when I try to do C-r for incremental backward search, it doesn't  
work.  Anybody knows how to enable it?  The lib seems a binding to GNU  
readline which does have it, so I guess the question is, how...

Cheers,
Alexy