The latest Long Term Support (LTS) release from Ubuntu has been with us for a bit over a month now, and I love it so far, on my laptop. This is Lucid Lynx 10.04, and will be supported until 2013 on the desktop, and more importantly, until 2015 on the server.
My servers are still on 8.04 though, the previous LTS, for good reason. 10.04 has PHP 5.3. While this is generally a better PHP, it has some compatibility issues with many Drupal, mainly for contributed modules, but some in core as well.
The long term solution to this is to find all PHP 5.3 compatibility issues and fix them in the code. This is a lengthy process though, and will not happen overnight.
So, in the meantime, there are several solutions for running PHP 5.2 on Lucid, some better than others.
In this post, we examine the different approaches, and the merits of each.