[plt-scheme] Why do folks implement *dynamically* typed languages?

Dave Herman wrote:
>> I suppose it could be called that.  DO you know languages that 
>> actually do this?
> 
> In the literature:
> 
>     http://www.citeulike.org/user/dherman/tag/type-dynamic
> 
> In history:
> 
>     Modula-3 (type REFANY)
>     Amber (type dynamic)
>     Quest (type Dynamic_T)
>     VB (type Any)
>     Cecil (type dynamic)
>     Typed Scheme (implicit)
>     ECMAScript Edition 4 (type *) <-- proposed

and ProfessorJ. Sorry for the omission.

Dave