Thank you for suggestions on how to tweak custom toplevels.

For a while now I have been thinking that there should be a fancy
alternative to the current toplevel. If I had the time, I would actually
go ahead and try to write one. But what would be a good feature list?

I can think of several improvements:

1) First, provide not only a toplevel but also a library that others
could use to make toplevel-like interfaces to ocaml bytecode engine.

2) Do not hardcode stdin/stdout communication into toplevel. Instead,
have a toplevel that communicates with the outside in a more abstract
way. Thus it should be relatively easy to create toplevels that are
equipped with line editing, that communicate through a graphical user
interface (in a natural way), that talk via Texmacs, etc.

3) Equip toplevel with pretty printers that can manage polymorphic
types, and essentially make it possible to pretty print _everything_. It
should be possible to create a toplevel linked to a graphical user
interface that shows pictures and typeset text as results.

4) Provide reasonable configuration options that allow one to customize
the toplevel in a sensible way (such as pre-installed pretty printers
and pre-open modules). Reading stuff _only_ from .ocamlinit is not fancy
enough.

What else can we put on the wishlist?

If only someone else did it :-)

Andrej