[plt-scheme] 'addons-dir and collections

Matthew Flatt writes:
 >  * Changed Setup PLT to install PLT-relative ".plt" archives (which
 >    typically contain a collection) into
 > 
 >      (build-path (find-system-path 'addons-dir) (version))
 > 
 >    In other words, installing a ".plt" file now tends to writes to a
 >    user-specific directory.

What does "PLT-relative" mean?  Does this only apply to .plt files in
$PLTHOME?  Also, if it puts the version number in the path name, does
that mean all .plt files need to be reinstalled when the user upgrades 
to a new version of PLT Scheme?  Or will this happen automatically?

What's the best way to distribute a collection?  Make a .plt file and
tell people to download it and run setup-plt?  Do they need to put it
in $PLTHOME first?

--dougo at ccs.neu.edu