> I noticed the the GPL (GNU Public License) is being 
> used in the program, but on your website you talk about 
> using Open Source. I thought those were different things. 

GPL is an open source license, but in the original meaning 
(that is, a "free software" license). The term was misused, 
especially by certain proprietary firms that were allowing 
code inspection but with extremely strict licensing (you 
can't modify the code, you can't reditribute it, and so 
on..). Therefore the term now used is generally "Free 
Software" instead of "Open Source" to avoid the confusion - 
this is actually state in the main page ("HTTrack is a free 
(GPL, libre/open source) and easy-to-use offline browser 
utility. ")