I'm pretty sure they've allways charged to licence their data.

If you're surfacing it on another site, I don't think t hey're going to care if you're using their tools, a Module from CPAN, or a homegrown perl script -- they're still going to want their licencing fee.

But if you're doing queries for personal use, you might as well havea local copy of all the data instead of going across the pipe and parsing the HTML everytime.