Amber Smalltalk

Amber Smalltalk. It is an open-source implementation of the Smalltalk programming language that is designed to run primarily within a web browser environment. Developed by Nicolas Petton, it compiles to JavaScript and integrates deeply with the DOM of a web page, enabling rich client-side applications. The language aims to bring the live, interactive development experience of traditional Smalltalk systems to the modern web.

History and development

The project was initiated around 2011 by Nicolas Petton, who was inspired by the desire to use Smalltalk for web development. Early development was influenced by the Squeak and Pharo environments, seeking to translate their interactive paradigms to the JavaScript ecosystem. A key milestone was the creation of the Amber IDE, a browser-based development environment that provided a workspace, a class browser, and a REPL, reminiscent of tools found in VisualWorks. The project saw active contributions from the Smalltalk community and was presented at events like ESUG conferences. Development slowed after its last major release in 2017, but the codebase remains available on platforms like GitHub.

Language features

As a dialect of Smalltalk, it inherits core features like pure object-oriented programming, dynamic typing, and reflection. It introduces syntax and libraries specifically for web interaction, such as seamless calls to JavaScript code and manipulation of HTML elements. The language includes a foreign function interface to interoperate with existing JavaScript libraries like jQuery. It supports blocks and closures, and its class library is a compact subset of the common Smalltalk-80 standard, optimized for the browser context. Unlike some Smalltalks, it does not implement green threads or its own virtual machine, relying instead on the JavaScript runtime.

Implementation and environment

The compiler is written in itself, following the bootstrapping tradition of Smalltalk, and translates source code into JavaScript. The runtime is a JavaScript library that provides the foundational object model and core classes. The primary development environment is the Amber IDE, a single HTML file that loads the entire system, including the compiler and class browser, into the browser. This environment allows for live coding and incremental compilation, where changes to code are immediately reflected. It can also be used in a headless mode with Node.js for server-side scripting or testing.

Relationship to other Smalltalk dialects

It is most directly comparable to Pharo and Squeak in its syntax and semantics but diverges by targeting the web browser as its primary platform. Unlike VisualWorks or VA Smalltalk, which produce standalone executables, it compiles to JavaScript. It shares the goal of live programming environments with Lively Kernel and Morphic-inspired projects. While Dart and TypeScript also compile to JavaScript, it is distinct in being a full Smalltalk system rather than a new language. Its class library is less extensive than that of GNU Smalltalk, which is designed for scripting and server-side use.

Applications and use cases

Its primary application is building interactive web applications and rich Internet applications where the Smalltalk development experience is desired. It has been used for educational tools, data visualization projects, and interactive demos that run directly in the browser. The environment is suitable for teaching object-oriented programming concepts on the web without requiring students to install traditional IDEs like Eclipse. Some developers have utilized it for prototyping user interface logic or creating dashboard widgets. While not as prevalent as frameworks like React or Angular, it serves niche projects within the Smalltalk and functional programming communities interested in client-side execution.

Category:Smalltalk programming language family Category:JavaScript programming language family Category:Cross-platform software Category:Free software programmed in JavaScript Category:Programming languages created in 2011