A minor limitation of cduce is that all ocaml types must be declared in cduce. This is cumbersome when trying to use an ocaml library from cduce.
I've created a small patch to cduce to allow to use ocaml types directly in a cduce program.
The patch is available in my personal darcs repository and pending to be integrated in the main tree.
The repository is here: http://web-cduce.pps.jussieu.fr/cgi-bin/darcsweb.cgi
and the tree can be retrived via darcs with