I noticed that the release notes of Wine 1.9.3 announced a "new
version of the Geck engine based on Firefox 44".

Alas, none of the many sf.net mirrors I tried carries
http://*.dl.sourceforge.net/project/wine/Wine%20Gecko/2.44/ .

The Wiki at https://wiki.winehq.org/Gecko refers to
http://dl.winehq.org/wine/wine-gecko/2.40//wine_gecko-2.44-x86.msi
which does not exist either.  (Note 2.40 vs 2.44.)

And http://sourceforge.net/projects/wine/files/Wine%20Gecko/ does
not seem to carry a trace, either.

Gerald