The EUPL also has legally binding translations (since they are legally equivalent, is "translation" the technically correct term?) into a lot of languages and a comprehensive compatibility chart.
It would be interesting to draft a wide array of ISC-equivalent licenses in different languages+jurisdictions. If you could make sure licensees reference the right license text for their jurisdiction, then you could even remove some of the duplicate language like the warranty distinction between DIRECT and CONSEQUENTIAL, which are apparently interchangeable in some jurisdictions.
