This screencast shows you how to create a report that lists a websites using a particular technology but not another one.
To find technologies not using other technologies, create the technology report you are interested in and then select the green 'Filter' button on that report.
On the Technologies tab of that report type the name of the technology you don't want to see, it will appear in a new section below, you can then change the 'Using' drop down to 'Not using', 'Used to use', 'Never used'.