OpenAI - contrary to its name, it is not open-source enough anymore.
Wolfram Mathematica - a lot of academicians (read Physicists) still use it for the ease of writing programs, but there is no open source alternative.
looker (i think there's already some projects trying)
OpenAI - It's bad to keep the whole power of AI between the hands of one corporation, doesn't matter if it is OpenAI, Microsoft, or Google, I think the power of AI should be accessible equally by everybody.