There’s a very simple question to ask web hosting companies that provides a pretty good first approximation to whether they’re any good or not:
For how long has PHP 5 been available on all your servers?
Simple? Yes. Irresponsible? Absolutely. However, the beauty of this metric is that without the option of time travel, it’s impossible to game, but at the same time, it is pretty effective at sorting out the sheep from the goats.
The key date to look out for here is 13 July 2007: the best web hosts started rolling out PHP 5 when it was in version 5.1 at least, and quite possibly when it was in version 5.0, but cheap and nasty web hosts didn’t do anything about it until the end of life announcement for PHP 4 just over a year ago. Some of them still have servers that don’t have PHP 5 installed on them, despite the fact that PHP 4 is now officially dead, buried, pushing up the daisies, and no longer supported by a lot of popular software.
Now this is not the only matter at stake — you need to take into account questions such as uptime, speed, and technical support. It may also not sound like a relevant question at first glance — pretty much all web hosts these days offer PHP 5.2.6 to new customers — but it does give an indication of how up to date your hosting package is likely to be with future changes and innovations, as well as raising serious questions if they’re not. After all, if a company needs a massive kick in the pants from the entire open source community to give you three year old technology rather than seven year old obsolete technology, what other shortcomings does it have?