MySQL 4.1.7 has just been declared a production-ready 'general availability' release. Before you all rush out and upgrade, note that a number of people have reported some problems with MediaWiki failing during installation on MySQL 4.1, due to a change in the authentication protocol.

I've done a little testing, and it looks like the proper fix for this is to recompile PHP after you've upgraded MySQL, so it uses the updated MySQL client libraries.

The other workaround is to fiddle with the user account to set it to a backwards-compatible mode (if you upgrade an existing database from 4.0 to 4.1, existing accounts should already be in this mode), as described here: http://dev.mysql.com/doc/mysql/en/Old_client.html

-- brion vibber (brion @ pobox.com)