I wrote about this 20 years ago:
http://digital-majority.wikidot.com/forum/t-5766/software-pa...
In the meantime, Ireland removed their 0% tax over patent royalties, but Holland kept it at 0%.
Your 20y old site gave me https errors when I tried to click it, fyi
Oh it was the EU that closed it down? didn't even know this ended as an option