VisualWorks: A Comprehensive Overview of a Cross-Platform Smalltalk Implementation
VisualWorks, a powerful and flexible development environment, represents a significant evolution of the Smalltalk language, originally developed in the 1970s. This cross-platform implementation, which dates back to the mid-1980s, has undergone multiple transformations, preserving the core values of Smalltalk while offering a rich, modern development system suited for a wide range of applications. Understanding VisualWorks involves examining its historical context, technical structure, features, and its place within the larger landscape of programming languages and development environments.
Historical Context: Origins and Evolution
The lineage of VisualWorks can be traced back to the first implementation of Smalltalk-80 at Xerox PARC (Palo Alto Research Center) in the 1970s. Smalltalk, created by Alan Kay, Dan Ingalls, and others, was a pioneering object-oriented programming language that introduced concepts like dynamic typing, garbage collection, and the integrated development environment (IDE). Smalltalk-80 was the version that set the standard for object-oriented programming (OOP) and influenced many subsequent languages, including Python, Ruby, and Java.
In the late 1980s, a group of Smalltalk-80 developers who had previously worked at Xerox PARC formed a company called ParcPlace Systems. Their goal was to further develop Smalltalk-80 and transform it into a commercially viable product. This commercial version of Smalltalk-80 was initially named ObjectWorks, and later rebranded as VisualWorks in the early 1990s. VisualWorks maintained the spirit of the original Smalltalk-80 language while introducing new tools, enhancements, and a more user-friendly interface for developers.
In 1999, Cincom, a global software and IT services company, acquired the VisualWorks product from ParcPlace Systems. This acquisition allowed VisualWorks to continue evolving under the umbrella of Cincom, ensuring its survival and growth in a competitive market.
Technical Structure: The System Image
At the heart of VisualWorks is the concept of “images,” a unique feature of the Smalltalk development environment. An image is essentially a snapshot of the entire system’s state, including all objects, classes, methods, and user-defined code. The idea behind the image-based architecture is that developers can save their progress and resume work at any time, effectively creating a persistent and recoverable environment.
When developers work in VisualWorks, they interact with a live system image. This image can be saved, loaded, and modified, enabling real-time development. The system is highly dynamic, allowing for the continuous addition and modification of objects without needing to restart the application or the environment. This live programming model is one of the distinguishing features of VisualWorks, as it allows developers to make changes on the fly and immediately see the results of their work.
Cross-Platform Development
VisualWorks is designed to run on a variety of operating systems, including Windows, macOS, Linux, and several versions of Unix. This cross-platform capability is one of its most significant features, allowing developers to create applications that can run seamlessly across different environments without requiring modification. The ability to write code once and deploy it across multiple platforms is a major advantage in modern software development, particularly for businesses that operate in heterogeneous IT environments.
The multi-platform features of VisualWorks extend beyond simple compatibility. For example, VisualWorks allows developers to create graphical user interface (GUI) applications that can automatically adapt to the widget styles of different platforms. This is made possible by the abstracted GUI framework, which abstracts platform-specific details, enabling the same code to produce native-looking applications on different operating systems.
The system also includes a virtual machine (VM) that is platform-dependent, but once the appropriate VM is installed for a given platform, VisualWorks applications can run without modification. This flexibility has made VisualWorks a popular choice for developers looking to create cross-platform solutions.
Features and Capabilities
VisualWorks is a fully integrated development environment that provides a range of powerful tools for developers. Some of the key features of VisualWorks include:
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Rich IDE: The integrated development environment in VisualWorks is robust and includes a range of tools for coding, debugging, and testing. The system includes an object browser, which allows developers to explore and navigate the entire object-oriented system, and a GUI builder, which simplifies the process of designing and implementing user interfaces.
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Live Programming Environment: One of the most distinctive features of VisualWorks is its live programming model. In a live environment, developers can interact with objects, modify their behaviors, and immediately see the effects of their changes. This real-time feedback loop encourages experimentation and rapid development, making it particularly suited for prototyping and iterative development.
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Image-Based Persistence: As mentioned earlier, VisualWorks uses an image-based architecture to manage the system’s state. The image captures the entire system’s state, including the code, objects, and methods, providing developers with a persistent environment that can be saved and restored. This approach simplifies application development by eliminating the need for manual save/load operations, as everything is stored in the image itself.
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Cross-Platform Support: VisualWorks runs on multiple platforms, making it a versatile tool for developers who need to build applications that work across various operating systems. The ability to create a single codebase that runs on Windows, macOS, Linux, and Unix is a major advantage for teams working on diverse projects.
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Active Community and Support: VisualWorks benefits from a vibrant community of developers who contribute to the ecosystem through third-party tools, libraries, and resources. This community-driven development helps keep VisualWorks up-to-date with modern trends and best practices in software development. Moreover, the availability of a non-commercial version allows developers to use VisualWorks for free, ensuring accessibility for educational purposes and independent developers.
Commercial and Non-Commercial Versions
VisualWorks is available in both commercial and non-commercial versions. The non-commercial version is fully functional and includes all the features of the commercial version, making it a great option for individual developers, students, and hobbyists. The commercial version offers additional support, services, and licensing options for organizations that need enterprise-level capabilities.
The commercial version of VisualWorks is used by a wide range of industries, including finance, healthcare, and telecommunications. Its ability to create highly scalable and flexible applications makes it an ideal choice for companies that require customized software solutions. Cincom, the owner of VisualWorks, offers comprehensive support and consulting services to help businesses maximize their investment in the platform.
Applications of VisualWorks
VisualWorks is suitable for a wide range of applications, including but not limited to:
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Enterprise Applications: With its robust and scalable architecture, VisualWorks is well-suited for creating complex enterprise applications that require high performance and flexibility. The platform’s support for object-oriented programming and dynamic development makes it ideal for building applications that need to adapt quickly to changing business requirements.
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Prototyping and Rapid Development: The live programming environment and the image-based architecture make VisualWorks a great tool for prototyping and rapid application development. Developers can experiment with new ideas, modify objects in real-time, and quickly iterate on their designs.
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Cross-Platform Applications: VisualWorks is particularly effective for developing cross-platform applications that need to run on multiple operating systems. Whether it’s a desktop application or a web-based solution, VisualWorks ensures that developers can create applications that work seamlessly across different platforms.
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Academic Use: Due to its open-source nature and the availability of a non-commercial version, VisualWorks is often used in academic settings to teach object-oriented programming and software engineering concepts. Its interactive development environment and rich set of features make it an excellent tool for students learning about software development.
Conclusion
VisualWorks stands as a testament to the enduring influence of Smalltalk and the power of dynamic, object-oriented programming. Its image-based architecture, cross-platform capabilities, and live programming environment provide developers with a unique and powerful toolkit for creating modern applications. Whether used for enterprise solutions, rapid prototyping, or academic instruction, VisualWorks offers a versatile and robust platform that continues to thrive in a rapidly changing technological landscape.
The future of VisualWorks looks bright, as its community continues to innovate and build upon the strong foundation laid by its creators. The product’s ability to evolve and adapt to new technologies ensures that it will remain a valuable tool for developers seeking flexibility, power, and scalability in their software development projects.