Kernel-Ex Version 4.5.12 says it's intended to run Firefox 8.0.

While FF 8.0 does load, it's crashes almost everytime I close it, and
often when I clear the history (cache, cookies, etc). A few times this
crash locked up the whole computer, which has not happened to me in
years.

Before this, I had the previous version of Kernel-EX, and was running FF
3.0.0.28. That one dont crash, even though that version loads slower
than molasses in January (up to 2 minutes), and recently keeps giving me
problems on some websites, such as "no longer supported" messages on
sites like Youtube. And it also tends to get a lot of script errors
too. But this ver dont crash.

Just for the heck of it, I installed FF 4.x (most recent ver of 4).
Same as ver 8.0. Crashes when closing and sometimes when I clear cache.

I finally just uninstalled all of them and went back to version 3.

Kernel-EX dont seem to work as it claims, at least not for FF. I guess
it's time to start using XP on the internet, there just is no browser
that works in 98 anymore. My old favorite, K-Meleon gets a script error
every 5 minutes, Seamonkey (for 98) is also too old, and i dont use IE.
(it's not even installed). I wont touch Opera with another man's _ick
on the end of a 10 foot pole. I looked into a few others and none are
suited for Win98 anymore.....

I'm not real fond of XP, but I guess the time has come to force myself
to like it.... I know I'll miss W98se.