Smalltalk is an object-oriented programming language that was developed in the 1970s at Xerox PARC. It is known for its simplicity and flexibility, allowing programmers to create complex applications with ease. Smalltalk emphasizes the use of objects, where everything is treated as an object, making it a pioneer in the field of object-oriented programming. One of the key features of Smalltalk is its interactive development environment, which allows programmers to write and test code in real-time. This environment encourages experimentation and rapid prototyping, making it a valuable tool for learning and development. Smalltalk has influenced many modern programming languages, including Ruby and Python.