MovableType: problems with EarthLink

As I noted, I've been "Playing With Movable Type".  Looking around the MT support bboards, several people said they'd had some glitches installing MT on Earthlink hosted web sites.  The source of the problem is that Earthlink is running Perl  5.00404, which the MT people claim is over five years old.  That struck me as odd: what's a major ISP like Earthlink doing running a 5-year old version of Perl?  I have an acquaintance at Earthlink, so I asked him.  His answer was interesting.

He passed the question on to an engineer in the web hosting group, who acknowledged that this was an issue on one of their lists of things to do, but not a very important one: one that they might not even get to anytime soon. 

His next comment was most interesting:

" ... it seems certain to cause more issues than it cures, since we'd be upgrading software that our customer's software (which we don't control, and can't test, and can't fix), depends. You end up with customers yelling at you because you didn't upgrade, and then different customers yelling at you because you did (as we're seeing now with the recent FrontPage upgrade)."

He's right: Perl 5.6 has significant differences from Perl 5.004, so doing a blanket upgrade would certainly break stuff.

My suggestion is to make the version configurable so that customers can have it either way.  Current customers get left at the old version, but they have the option of changing it; new customers get the newer version by default. 

But of course that has issues of its own.  The only way to run a large site is to simplify and strive for uniformity.  Earthlink must be running tens or even hundreds of thousands of web sites, small and large.  Anyone who's ever been in the ISP business will tell you that the smaller the customer, the more trouble they are to serve; it's a wonder Earthlink keeps it all running at all.