[Tcl] has been a testbed for safe interpretation since before [Java] existed (at least under that name).
As [security] becomes ever more important, perhaps attention will return to Tcl just for this feature.

Recognize, first, its uniqueness.  Nominally peer languages--[Perl], [PHP], [Python], [Ruby], and
others--have security features, but none of them really boast the power and flexibility of 
[interp]s [[explain]].

[Christoph Drube] - Is this really true? I'm using safe interps all the days with great success for import/export filters - so there is no file type it cannot read/create :-) One thing more to stay with Tcl ...

[KJN] - It's true. PHP has a safe mode, but even the PHP manual cannot give you an authoritative list of the functions that are restricted or disabled by safe mode [http://www.php.net/manual/en/features.safe-mode.functions.php].