goodbye, chatzilla

Can anybody recommend a good, simple Firefox IRC client to replace Chatzilla, which doesn't work on Firefox Quantum?

I am sad about Chatzilla. Especially since Quantum isn't noticeably faster for me--in fact sometimes it seems slower--so I'm not convinced the improvements are worth the loss.

(Please don't tell me to switch to Google Chrome. Google already knows enough about my online life.)

Never mind. I just saw that DownThemAll doesn't work anymore either, and the extension Mozilla is supporting as a replacement has gotten a lot of reviews saying it doesn't work. So I think I'm going to try to revert Firefox back to its pre-Quantum version.