Smalltalk

Smalltalk is an object-oriented, dynamically typed, reflective programming language.

 

Smalltalk was one of many object-oriented programming languages based on Simula.^[10] Smalltalk is also one of the most influential programming languages. Virtually all of the object-oriented languages that came after—Flavors,^[11] CLOS, Objective-C, Java, Python, Ruby,^[12] and many others—were influenced by Smalltalk.

 

https://en.wikipedia.org/wiki/Smalltalk