Minimal mod to make it works on Win 8.1 x64 (Build upon FireFox 136.0)
Works on Win 7 + VxKex, a sort of. Languages, dictionaries, themes and plugins works but can not open any web page.
Update - Works on Win 7 without VxKex, but you had to make another profile and switch to another, if one does not display pages.
No portable mode, because often profile switching. (Build upon FireFox 138.0.2)
Floorp 12 Works on Win 7 - no need for VxKex, not fully patched - xul.dll is from another project!
