LWN notes:
MySQL 4.1.0, a new version of the popular Open Source Database, has been
released. It is now available in source and binary form for a number of
platforms from our download pages at http://www.mysql.com/downloads/ and
mirror sites.
Watch out, 4.1.0 is an Alpha release and probably not the best thing for production use. Granted, MySQL’s idea of Alpha is probably much more stable than others, but throw it on your testbed, not your server.