VAST Platform is a development environment which consists of the Smalltalk language and library of code together with many tools to support application development. This powerful Smalltalk development environment enables you to quickly develop, manage, and package complex applications, including client-server applications. The Calculator is one simple example of an application written using VAST Platform.

The Smalltalk language and library of code are so powerful and flexible because they are based on tailorable, reusable software components. Developers have tools at their disposal to examine, create and alter these components. The development environment also has tools to share these software components among a team of developers and to deploy a finished application to customers. See team concepts for an introduction to how VAST Platform supports team programming. For a more thorough understanding of this very robust programming language, refer to the Programmer Reference.

If you program visually, VAST Platform provides a WYSIWYG editor to build user interface to your application; if you write code, Instantiations provides an add-on product, WindowBuilder Pro for Smalltalk to do the same thing using common widgets rather than visual parts.

In VAST Platform, the basic development environment is seamlessly integrated with the visual programming tools. Thus, you can use software components that you create in the basic development environment in visual applications, and view programs created with the visual programming tools within the basic development browsers. To learn about the visual programming tools, see Visual Development Tools.