In addition, Compaq offers the Enterprise Toolkit that provides the tools for you to develop, edit, compile, build, and debug applications for Tru64 UNIX or Windows from one desktop environment. The risk associated with completely reengineering some older applications is high. Many applications are large, complex, poorly documented, and not well understood by their current maintainers. Encapsulating a legacy application can be less risky than reengineering and can be the first step in a rewrite. Over time, pieces of the legacy application can be rewritten, while the older version of the application remains stable and available.
Encapsulation also allows developers to reuse code, saving time and resources.
The disadvantages to encapsulation include more complex maintenance efforts and the inability to make changes to the underlying code. If the legacy application was unstable or hard to maintain, the encapsulated application will not be any better, and might be made worse because of the wrapper. Batch processing programs are well suited to user interface encapsulation. Applications that do screen management could have their older character-cell interface encapsulated using COM for Tru64 UNIX, providing users access through newer Windows NT style dialogue boxes. If you choose to encapsulate a database using COM for Tru64 UNIX, the database could be accessed from parts of a distributed application running on other platforms.