The short version - the site was running an incredibly antique version of TikiWiki
which it turns out had security holes you could drive an ocean liner through, so not good. Unfortunately the automated upgrade refused to work correctly, and insisted on giving me a completely broken site instead. Which is more secure, to be sure, but not especially useful. So... site has been down while I manually rebuilt it from scratch with the latest Tiki (4.2).
Hyperfiction, photo galleries, and the forums are gone for now, and may or may not return in the future. All the old blog posts going back to 2001 are still here - looking through it there's some rather embarrassing material in there, in hindsight
. And I hadn't realised 'till now that I'd started thinking about dreamcast emulation way way back in early 2002. Wow. It has been a while.
 I looked at a few other CMS/blog options, but in the end it would still have been more work to switch to something else, and Tiki is really quite nice when it's configured properly.