> Could you offer automated compression to 7zip? It
> has a much better ratio than zip /tar/gzip.

The only zipping Httrack does is to store the unmodified html files for
internal processing. 
In dir:   14741 File(s)    289,194,448 bytes
7z:                          3,367,476
rar                          4,452,922
rar as zip                  56,443,069
cache (20G mirror)          76,720,590 new.zip
The cache would be much smaller.

> You also could offer your "without installer"
> download in a 7z sfx archive...which would be about
> 1MB less than you current .zip archive, and would
> also allow people who can't open zip to open the 7z
> archive.
Probably a good idea. open source/free is the way to go.