Nope!  In fact, Frontpage won't even work with the site anymore, as it is indeed dead and the extensions it needs are no longer installed.

You are welcome to use any program you like, as long as you adhere to a general design theme that is stylistically similar to the main site.  Azurah did a great job with the Planescape subweb; it's familiar, but different.

As far as software, the final version of Microsoft Expressions (the successor to Frontpage) is free to download now, and will work well for beginners.

Foul