On 1/7/06, Gregory Seidman <gsslist+ruby / anthropohedron.net> wrote:

> I'm not clear on what openness we're talking about. Do you mean one or more
> of the following:

> 3) duck typing allows unintended objects to be used in unintended ways
>
> 4) the ability to add/replace methods in existing classes allows library
>    internals to be inspected or modified

These two.

Which are considered as features by most, but often as vulnerabilities
by outsiders :)