You started with a laundry list, I didn't. When it comes to that, CL is hard to beat. "Playgrounds"? What about reshaping the whole program on the heap while it's running, almost without limitations? Including persistent object databases if you have those (one might argue that without the ability to do that, transparently integrated object databases are quite difficult to pull off). You can implement any kind of workspaces or scratchpads or playgrounds (or what's the nom du jour for that ancient feature, dating back to Smalltalk-80, if I'm not mistaken) based on this solid foundation. But not the other way around. Many people don't need any of that, though. Certainly it's not the focus for the above mentioned server use of Go.