A compiled programming language with Korean keywuords, written in Rust - xodn348/han
I remember our professor at university (Gothenburg, Sweden) was teaching us object oriented programming and her example code had variable names and method names in Swedish because Java could deal with utf8 already beck then in 2008.
We were trying to convince one of the Arabic students to send in his stuff in Arabic, but he was too afraid.
Excel does it for its formulas. It ends up being just a pain in the ass when you are looking online for info (which means it ends up increasing the barrier of entry, as most stuff online is in English).