Also, out of curiousity, what drives the decision on which version of PHP to install?? I was surprised to see that the current SME 7.2 installed PHP 4.3.9 was originally released in Sept '04 (http://www.php.net/releases/).
SME Server is based on CentOS 4.5, which in turn is based on RHEL4. To minimize maintenance of packages SME Server uses the deafult upstream packages , which CentOS does as well.
Although the support for PHP 4.3.9 will seize, there will be security updates for a bit longer:
The PHP development team hereby announces that support for PHP 4 will continue until the end of this year only. After 2007-12-31 there will be no more releases of PHP 4.4. We will continue to make critical security fixes available on a case-by-case basis until 2008-08-08. Please use the rest of this year to make your application suitable to run on PHP 5.
As soon as SME Server 8 is released there will be support for PHP 5 supplied by the base, as this is based on CentOS 5, which comes with PHP 5.1.6 as default version. Until that time sponsor development with everything you have: bug fixing, testing, documentation, money or whatever you can think of! The sooner we will have SME Server 8!
