>> A layman's explanation is much appreciated. :)
>
>> 10 seconds on google:
>
> I spent about 10 minutes reading. :) That is why I asked for a layman's
> explanation. A flurry of acronyms and high tech jibber jabber is not a
> layman's explanation. :)
>
> Be nice to us old folks Calvin!
>
> Darrell

+1.  Not very many people know C++ internals well enough to really know
what is going on with visibility support.

The claims on that website are a bit overinflated (to their credit they
did state this).  My testing on TDE has indicated a slight but noticeable
speed increase with something like a 10% decrease in core library size. 
To be fair this test was run on a heavily loaded development system over
NFS, so a lightly used system with lots of RAM and a fast hard disk may
notice no speed improvement at all.

TDE needs to be built with the visibility flag set for arts, tdelibs, and
tdebase to see the improvements.  I would treat this flag as beta quality
for now until we get widespread testing of the resultant code, as older
versions (3.x) of gcc had problems implementing visibility support on KDE.

I hope this helps some!

Tim