Offline versions are history
We used to offer offline versions of the site back when David Howe owned the site. This relied on code written but never documented well by David. Now that the site is owned by Fergus Duniho, offline versions will no longer be made. While some of David's old code for making offline versions remains in place, some of it has been replaced by code that works only for online pages. Moreover, this site has been moving in the direction of being more database-driven and interactive instead of being a bunch of static HTML pages. In time, the code for making offline versions may be removed completely, though it is not high priority. In the meantime, it is just not being used for that purpose. This site functions best as an online website, and it is easy enough for most people to get on the internet these days.
One problem with trying to maintain the pages to work offline is that we have had to link to other pages on the site only with relative links, and the relative links have had to be of the dot-dot-slash form. This has caused trouble when pages have moved or someone forgot what directory level a page goes in. It is much simpler to begin relative links with a single slash. This properly orients the relative link no matter what directory level it appears in. From now on, this is how relative links should be done. This is best practice for online links, though it doesn't work for offline links.