Joel Spolsky (of the Joel on Software fame) has started a series of blog entries shedding light to what they've done at Fog Creek in the past.

In the 3rd installment, Joel tells about how they needed to port their ASP-based application to PHP so that it would run on UNIX boxes as well as Windows. Their solution was to build a custom ASP-to-PHP compiler, relying on a variation of Hungarian notation among other things.

What I don't get is this: If your goal is to make your application portable, for how long is it worth the effort to develop the ASP version and make sure that the custom compiler can keep up with what they're doing? Wouldn't it be easier to go the other way? I.e. compile once from ASP to PHP and then keep on doing PHP only -- deploying on Apache on both Windows and UNIX.

I'm certain that there were valid reasons for sticking with the ASP codebase as the master some 2 years ago but I have to wonder if Joel & Co. should really be looking at switching to a portable language like PHP/Java/Python/Ruby instead of maintaining their own portability layer?