Squeak

About

Squeak is a modern, open-source Smalltalk programming system with fast execution environments for all major platforms, including macOS. Its Morphic framework is designed to make graphical, interactive application development and maintenance low effort. Projects built with Squeak span education, multimedia, gaming, research, and commerce.

Squeak follows Smalltalk's approach that everything is an object, and objects collaborate by exchanging messages. The system is implemented in itself: the compiler, debugger, and programming tools are all Smalltalk code that users can read and modify. Its tools support browsing, searching, and writing Smalltalk code, and the current 6.1 release is available for macOS as a download. On macOS, you must drag the included .app file out of your Downloads folder to avoid translocation, since mv will not work.

With Morphic, all graphical objects are tangible and interactively changeable, which shortens feedback loops during development. The site also describes a community with mailing lists, a wiki, and a bug tracker for reporting issues in Squeak.