As usual, there are many security enhancements in this newest release of PHP 5.x series. So as Ilia put it,
Given the significant number of security issues that were resolved, my recommendation is that all users of PHP, especially those running really old versions (You know who you are 😉 ) consider upgrading to this release as soon as possible. Not only will the security of your setup increase, but the stability and the performance of your PHP will improve as well.
One of the security issue that has been fixed, which is interesting to me, is to prevent search engines from indexing the PHPINFO() page. I have posted about this issue couple months ago (in bahasa). You can see more about this in Ilia’s blog. It’s a simple fix, but very important for sloppy programmer like me. 🙂
There are also many improvements in term of performance, especially in Windows environment. Which is why i’m so excited with this release, am downloading now, and how fast it goes.