Waterfox works fine with all my legacy extensions in multi-process mode.
Pertinent part is, "my".
Multi-process breaks some or parts of some extensions.
BTW, Waterfox still supports Windows XP despite of code changes made by Mozilla.
How?
Seemingly some old version, 53.0.3
did?
Current looks to be Win7+ "6.1", & x64 at that, (& regardless of what their website might show [depending on how you look at it]).
Really? Why? No one else does [care].
I would, if it were available.
Fire 750, bring back 250.
Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.19) Gecko/20110420 SeaMonkey/2.0.14 Pinball CopyURL+ FetchTextURL FlashGot NoScript