Somebody emailed me about our missing search engine. This is the response I typed up. Maybe it will help somebody else:

I suppose we could blame it on Google, but it's probably a good thing to do in the long run.
Google has been pushing Websites to adopt https:// security, which is a good thing. It got to the point where Mudcat's owner Max Spiegel decided to go along with Google and increase security, but that meant that Max had to move Mudcat to a new platform. It's a difficult job, and it will take Max some time to get a number of functions back online. The most notable one is the "search" function.
We've always had a number of search engines, and I usually use a variety.
I wrote a description of our various search engines and how to use them in our FAQ: https://mudcat.org/detail.cfm?messages__Message_ID=196922

If you have trouble finding something, give me a holler. I'm pretty good at finding stuff.
-Joe-
joe@mudcat.org