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

On May 31, 2007, at 5:09 PM, jerzy.karczmarczuk at info.unicaen.fr wrote:

> Matthias Felleisen writes:
>> I thought OCAML had Dynamic.
>
> In the sense of dynamic typing? I don't know about it.
> But the Clean language, quite Haskellish in general, has now
> Dynamics which is quite interesting! It permits to exchange
> code AND data between applications, something Scheme was always
> proud of.

1. The ML people invented Dynamic for heaven's sake.

2. Dynamic is what Grant asked for: a type in an SL that accommodates  
dynamic checking (say i/o via a network or db connection).