I find it interesting that a number of PLs were initially developed as educational or research tools but later expanded for general use. Some examples are Pasca

I find it interesting that a number of PLs were initially developed as educational or research tools but later expanded for general use. Some examples are Pascal, Scheme, Prolog. AFAIK many development languages are used in education so the distinction is rather fuzzy. Several Scheme implementations, e.g., Chicken, Chez, Gambit, are capable of producing almost any type of program. I'm most familiar with Chicken Scheme. Comes with a large "standard" library plus a broad range of available extensions. Its easy to use FFI adds to productivity. My experience anyway. Of course, mileage varies widely among users of any language.