Too Many Template Systems

I found an unexpected source of frustration while getting LiveWorks! online. The site is primarily an instance of WordPress1 but the mailing lists are handled by Mailman and the archives by Lurker. All three of them are simple to customize their outward appearance, but all three of them use a different template language. So now instead of having one site design, I have to have three very similar looking, but completely different design implementations2. Every time we want to update the common parts of the site, we have to do it in multiple places in completely different ways.

There must be a better way to do this. It’s great having all the power and flexibility of PHP in WordPress’s templates, but most themes don’t need it. Isn’t is possible to come up with some simple template standard to at least allow the common structures to be shared? The specifics of the page content will still need to be done for each program but that’s fine.

At the very least, could tool vendors that provide a web interface at least make it use HTML 4 and CSS or better?

1 – purely because it was the easiest thing, I'm not really sure it will scale as the site expands↩

2 – actually I wound up with only two because I left Mailman as-is as just highlighted the email interface instead of the web-based one↩