Official Website: http://www.ntop.org/. NTop-XTRA has now been discontinued.
The reason we have been forced to withdraw the packages is because the downloads were causing our paying customers problems with accessing our site. There was some very odd traffic patterns where many gigabits of data were being taken from the same range of proxied IP addresses. I have no idea what they were up to but their behaviour was causing us a big problem at a time when no company can afford to place barriers in front of their customers to do business with them. In a single day we had over 200 GB downloaded from our server. It would appear that our ISP has got wise to this and has begun to limit the traffic to our server. Unfortunately, there is no differentiation between download traffic and regular web traffic.
One of the download sites may have a copy, though I can`t guarantee exactly what they are storing.
Please don`t email asking for a copy because I don`t have one available. If I make one available publicly, then the problem we`re trying to solve will just come straight back. And don`t ask if we can email it because our email server won`t cope with that and I doubt yours will either. Sorry. If you are going to be pissed at anybody please direct your ire to whomever was abusing our service in the first place.