I know that the original Notepad++ is under GPLv2 so creating an open-source port is perfectly acceptable, but the Notepad++ name itself is trademarked by Don Ho, so calling itself "Notepad++" (for Mac) along with using an almost identical icon feels like it's crossing some boundaries.
From a quick glance Don Ho looks to be based in France, and a search of their trademark registry gives a current result for Notepad++: https://data.inpi.fr/marques/FR5133202
On closer look, I think you’re right. I also tried searching the USPTO trademark database by author and by product name and couldn’t find anything. I don’t know why I thought he had trademarked it. Maybe it could qualify as a common law trademark, but I’m really not sure as this is well outside my area of expertise.
