Sounds nice!

Do you know, Reinout, how hard has this namespaces approach been pushed?
 How large of Forth programs are there?

I believe Python has a mechanism for this kind of local namespaces, by
the way.  By default, namespaces are based on files.  However, if you
invoke the loader in the right way, you can load a package and specify
what namespaces it can see.  This was used in the Grail web browser to
allow secure execution of Python code within a web browser.  The
sandboxed code simply could not see global variables that are dangerous.

And to get obscure, I remember that one of the job-submission languages
on IBM mainframes, lets you connect the logical files of the program you
are running, to physical files of your choice; then, programs do not
ever open a filename in the general filesystem.  Instead, they talk only
to virtual file systems.  So, this idea of the "global" space being
specified by another component, has been used in some strange places!


-Lex