The O language is not really new, it is more of a logical evolution step for the APL-like languages. When it comes to ideological lines, O is a successor of K family (Arthur Whitney) of programming languages. However, it doesn’t share a single line of code with K5 and is implemented in Rust instead of C. O's development started in Dec 2016 and the language has been redesigned 5 times so far. Current design seems to be polished enough to be considered as 'stable'.