joomla/joomla-platform — pull request #1003 by realityking (2012-03-19 10:29:49+00:00)
Title: Remove a workaround for PHP 5.3.0 in JLanguage.

This raises the minimum requirement to 5.3.1.

Even Ubuntut 8.0.4 (the oldest still supported LTS) has PHP 5.3.2 and Debian stable has PHP 5.3.3 so I see no harm in requiring 5.3.1.