MediaWiki drops PHP 4 support
Wasn’t too happy to read this:
This is the first version of MediaWiki to require PHP 5. 5.1.x is recommended; 5.0 may work but is not well tested. (PHP 5.0 is no longer maintained; all PHP 5.0 users should upgrade to a current 5.1 release to ensure they have all security fixes.) PHP 4.x is no longer supported by MediaWiki. If you are unable to upgrade PHP, sorry, but you will have to stick with old versions of MediaWiki for now.
Luckily, the 1.6 branch will continue to be maintained for a little while, but eventually I will be forced to undertake the sticky, unsupported upgrade from PHP 4 to PHP 5 on my Red Hat Enterprise Linux box (losing automatic updates and coming up against a potential minefield of other compatibility problems).