UNIX and Windows hosts are excellent systems for program development and for many interactive applications. However, they are not appropriate for real-time applications. On the other hand, traditional real-time operating systems provide poor environments for application development or for non-real-time components of an application, such as graphical user interfaces (GUIs).

Rather than trying to create a single operating system that "does it all," the Wind River philosophy is to utilize two complementary and cooperating operating systems (VxWorks and UNIX, or VxWorks and Windows) and let each do what it does best. VxWorks handles the critical real-time chores, while the host machine is used for program development and for applications that are not time-critical.

You can scale VxWorks to include exactly the feature combinations your application requires. During development, you can include additional features to speed your work (such as the networking facilities), then exclude them to save resources in the final version of your application.

You can use the cross-development host machine to edit, compile, link, and store real-time code, but then run and debug that real-time code on VxWorks. The resulting VxWorks application can run standalone--either in ROM or disk-based--with no further need for the network or the host system.

However, the host machine and VxWorks can also work together in a hybrid application, with the host machine using VxWorks systems as real-time "servers" in a networked environment. For instance, a VxWorks system controlling a robot might itself be controlled by a host machine that runs an expert system, or several VxWorks systems running factory equipment might be connected to host machines that track inventory or generate reports.