That's not unusual, historically some software had prototypes in Lisp. Some managed to get into production. Some even proved very hard to replace.
But that was at a time when more people learned Lisp, there was less choice in tools and the eco-systems were smaller. In the 70s/80s one could buy ten years into the future with the right hardware/software and government/military was financing.
Take for example the Connection Machine CM 1, an early massive-parallel computer with 2^16 processors. It was initially developed largely for and with Lisp. You could program it in *Lisp from a Lisp Machine - one of the most expensive co-processors. Fortran and C was added then for certain commercial users. Very expensive stuff and at least ten years ahead.
But that was at a time when more people learned Lisp, there was less choice in tools and the eco-systems were smaller. In the 70s/80s one could buy ten years into the future with the right hardware/software and government/military was financing.
Take for example the Connection Machine CM 1, an early massive-parallel computer with 2^16 processors. It was initially developed largely for and with Lisp. You could program it in *Lisp from a Lisp Machine - one of the most expensive co-processors. Fortran and C was added then for certain commercial users. Very expensive stuff and at least ten years ahead.
Today the landscape looks different.