Hi Andrew: I posted this here before, but maybe it got lost (or moderated!). As you noted, this is fundamentally an osascript problem. The specific problem is that it is not handling default browser identification correctly. A quick fix for Jupyter notebook usage that doesn't involve editing any configure files (which you may forget to "unedit" after the bug is fixed) is to launch the notebook as follows: $ jupyter notebook --browser=Chrome (That's for Chrome users; modify appropriately.) It's a minor pain to have to remember to add that option when launching on a Mac. This does support using Chrome.