tenthumbs@cybernex.net says:

I also found a way to get Linux Netscape to use bzip2 for Content-Encoding just as it uses gzip. Add this to $HOME/.Xdefaults or $HOME/.Xresources.

I use the -s option because I would rather trade some decompressing speed for RAM usage. You can leave the option out if you want to.

Netscape*encodingFilters:      \
        x-compress :  : .Z     : uncompress -c  \n\
        compress   :  : .Z     : uncompress -c  \n\
        x-gzip     :  : .z,.gz : gzip -cdq      \n\
        gzip       :  : .z,.gz : gzip -cdq      \n\
        x-bzip2    :  : .bz2   : bzip2 -ds \n