Recently I’ve been making some new esoteric programming languages, or “esolangs”. I haven’t been actively writing new esolangs since 2011! Most recently I published a language named Jungle to the esolang wiki. The structure and control flow of a Jungle program resemble that of a binary tree. You can learn about the language and download a reference implementation at https://esolangs.org/wiki/Jungle.
write_char "Hello world!";