Well, Wolfram|Alpha. I switch from computer vision to parsing to machine learning on a daily basis. But I haven't used the workhorse mathematics functions like

Well, Wolfram|Alpha. I switch from computer vision to parsing to machine learning on a daily basis. But I haven't used the workhorse mathematics functions like Solve or Integrate in 3 years. Perhaps it would be better to call it a 'Domain General Language' for everything.